The Rough Cut by yurifuruta

The

Rough

Cut The diamond journey from a rough natural state to a perfect gemstone

The

Rough

Cut

Copyright © 2015 by Evelyn Furuta All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law. For permission requests, write to the publisher, addressed “Attention: Permissions Coordinator,” at the address below.

Amo Publisher San Francisco, CA This book is a student work. Any part of this book and any deliverable for this project were NOT produced for commercial purposes.

Printed in the United States of America

First of all, I would like to thank my family for believing in my potential and allowing me to have the opportunity to study at this school. Special thanks to Will Burke for all the support. For the last, I would like to thank my instructor, Ariel Grey, and my peers for all the feedbacks which were essential for the development of this book.

TA B L E O F C O N T E N T S

Introduction

CHAPTER 01

The history of diamonds

Diamond timeline

Diamonds and engagement rings

CHAPTER 02

Physical properties

Optical properties

Itâ&#x20AC;&#x2122;s a result of marketing

Color, dispersion & ref lectiveness

Faceting a gemstone: the critical angle

Start with carbon

Crystal structure

Fancy colors

Mines location

The Lapidaire

The Diamantaire

Molecular structure

Colors

30 Clarity

CHAPTER 03

Mining

Synthetic diamonds

CHAPTER 04

The diamond journey: from mines to retail

The 4câ&#x20AC;&#x2122;s

The cutting process

Types of cuts

60 Bibliography

THE ROUGH CUT INTRODUCTION

INTRODUCTION

This book will show how diamonds are so influential, all the journey this gemstone goes through from mining to retail, and also to reveal that this gemstone is incredible by its visual beauty which can be enhanced by human intervention, and specially by its physical properties. Diamonds have grading certificates for a reason, for your protection and your diamonds protection as well. Accuracy is very important to the beauty and value of your gemstone. It’s a good reason to remember the dates that your jewelry was bought or when it was given to you. Usually to go on with enhancing a stone, the clarity or inclusions have to be pretty visible. Thus, they drill holes into the flaws and bleach out the dark inclusions. This usually fills the holes or large inclusions that break the surface up with a compatible material. Diamonds are so valuable because the price of anything is determined by supply and demand. There is a great demand for diamonds and the appearance of a short supply is maintained by DeBeers Consolidated. The Seven major diamond mining countries of the world are: Botswana, Russia, South Africa, Angola, Namibia, Australia, and Democratic Republic of Congo They are also mined in these countries: Brazil, Guyana, Venezuela, Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Central African Republic, Tanzania, China, Indonesia, Zimbabwe, and India. These stones have been known since ancient times. They were originally used as a tool to carve other gems like lapis and carnelian. Ancient Greeks believed that diamonds were splinters of stars that had fallen on earth. Some said that they were the tears of gods. Legend has it that there existed an inaccessible valley somewhere in Central Asia; a carpet of diamonds covered it. It was patrolled by prehistoric birds of prey and guarded by venomous snakes. However, the truth is that the exact origin of diamonds is still a mystery, to scientists and geologists. Diamonds were formed as long ago as 3.5 billion

years, under conditions of great heat and pressure, deep inside the earth. This correlates with the earliest stages of the development of our planet, estimated to be in the region of 4.5 billion years old.Volcanic eruptions carried the diamonds to the surface of the earth millions of years ago. Diamonds are found in cone-shaped pipes of rock called kimberlitic. These pipes have been weathered and their diamonds dispersed by rivers to far-lying areas, such as coastlines. They should last for several million more years. Uncut diamonds hide the unique optical properties of the cut stones. Rough diamonds have a yellow, brown, or gray non-transparent skin which covers them. Only cutting can transform the unattractive ‘pebble’ into that crystal clear stone which, in clarity, luster and play of color surpasses all other precious stones. Most of the beauty of a cut diamond is in its amazing optical properties,particularly in the way it bends light, and its play of color. The round brilliant displays these properties in the cut state where all of the factors blend in-optical harmony with one another to create the highest degree of brilliance. Color and clarity are rarity factors given to us by nature. As the cut reveals these qualities, it also serves as a beautifying factor that is influenced by mans’ skill alone. Judgment of cut is based on one hand, on the impression gained at first sight, in which beauty and brilliance are judged purely on personal standards. Thereafter, attention must be directed to the proportions of the cut stone. Here, facet angles and proportions must be tested for accuracy. The grading of the quality of the cut is therefore always made up of two components: a subjective opinion of the brilliance effect, and an objective judgment determined by checking the craftsmanship and measuring the proportions. In contrast, to color and clarity grading, where a natural degree of rarity exists, in cut grading it is the manual skill of the stone cutter which is judged, because it has a direct influence on how beautiful the stone is.

chapter 01

Diamonds through history

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The first diamonds were found in the alluvium of the Golconda River in India. The exact date of its discovery is not known. An extract from an accounting book written in Sanskrit, in the 4th century B.C, reveals that diamonds were a trading commodity in India at that time. Perfectly beautiful and highly prized crystals were kept in possession by rich people and rulers. The diamond was popular as an amulet thanks to its exceptional hardness and other great properties. It was a symbol of courage and virilityâ&#x20AC;&#x201D;purely male qualities.In ancient Egypt people believed in the mystical power of diamonds. When four diamond rings were worn on four fingers of the left hand it would ensured that vena amoris vein of love would lead from the fingers straight to the heart. Placing diamonds or diamond powder on fingertips was believed to be the best way of ensuring the connection of love with eternity. Diamonds were probably brought to Europe by Alexander the Great. First, they were considered to be a mysterious rarity with magical and healing proprieties. It is believed that when Alexander the Great reached the Valley of Diamonds he saw its floor covered with gemstones guarded by giant snakes with deadly stares. But he succeeded in cheating them and took their diamonds. In ancient Greek diamonds were considered to be the tears of gods which fell down to earth. To point out the hardness of diamonds people used to name them adamas which means invincible. Plinius wrote about diamonds in his History of Nature 60 years B.C. The first uncut diamond appeared in Rome between the 1st and 3rd century. Marco Polo mentioned Ormuz as the main Persian diamond market in the 13th century. In this time Venice was the main market of diamonds in the West. From the beginning of the 13th century the majority of capital cities of Northern Europe maintained trading relations with Venice. Traders with silk and diamonds came from there to Bruges. Bruges became not only the centre of diamond trade but also a place where diamonds were processed.The diamond industry grew very quickly after that. Lodewijck van Berken, born in Bruges, invented the technique of cutting diamonds. This technique was kept secret for a long time. It was not until the 14th century that clear octahedrons were first polished on a wooden or copper pad covered

4 t h

DIAMONDS THROUGH TIME C.01

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THE HISTORY OF DIAMONDS

with diamond powder. This method was previously used to work gemstones and ivory, however in the case of diamonds, this was a lengthy process. Since the 15th century new methods of diamond processing were developed and unsquared stones were cut by cleaving. In the course of cutting, the original shape of the stone was still kept. Pyramidal shape diamonds were set into rings. The main purpose of processing diamonds was to get rid of surface roughness and impurities. Samples of these stones were found in fragments of jewelry and old pottery. The invention of cutting on a steel pad covered with diamond powder offered cutters more possibilities to work stones. At the end of the 15th century the table cuts, such as shapes of rhombus, square, rectangle and rose cut, appeared. The discovery of a direct sea route to India by Vasco de Gama in 1498 shifted the trading centre from Venice to Lisbon. Antwerp became the most important diamond trade centre since the end of the 14th century. Diamonds were considered to be a perfect symbol of eternal bond. The tradition of unending love has been maintained for several centuries already. The first notion of donating a diamond as a unique symbol of love came from the 15th century. The tradition of donating a diamond ring as an engagement ring was very first introduced by the archduke Maximilian I of Austria in 1477, when he gave it to Mary of Burgundy. Since then the tradition

with these rings has spread all over the world not only among the aristocratic and industrialist families but also among ordinary mortals. In the Golden age of the sixteenth century Portuguese Jews and Italian merchants had most of the control over diamond business. In the 17th century diamonds began to be cut in many different shapes like oval, drops, marquise and others. Specialists who cut the stones however came from Antwerp and worked in the highest floors of houses where light was the best.By the end of the 18th century the Indian mines were exhausted and although the first mines in Brazil were found in the second half of the 18th century, the prosperity of Antwerp was not restored. In the second half of the 19th century, Henry Morse of the USA discovered the first modern brilliant cut after extensive experimentation which was later perfected, mathematically substantiated and described by Marcel Tolkowski in 1919, in the USA, who is considered to be the inventor of the modern brilliant cut. In 1871 the De Beers brothers, owners of a small farm in Kimberley in South Africa gave permission to Dutch diamond hunters to prospect on their own land. The research showed that the land was heaving with diamonds. In 1888, De Beers Consolidated Mines Limited was established, the forerunner of the firm that still plays a very important role on the diamond stage.

T HE H I S T O R Y O F D I AM O N D S

Perfectly beautiful and highly prized crystals were kept in possession by rich people and rulers. The diamond was popular as an amulet thanks to its exceptional hardness and other great properties

DIAMONDS THROUGH TIME C.01

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DIAMOND TIMELINE

Diamonds have a history dating back to ancient times. As it turns out, diamonds have been valued for their quality and unique beauty for thousands of years. Diamonds are not simply a modern symbol of love and commitment. Below is the diamond history timeline of major events recorded in the history of one of the world’s favorite precious stones.

300 BC

A Sanskrit manuscript makes what is one of the first documented references to diamonds. India is the earliest known source for diamond knowledge

100AD

Pliny writes about diamonds in his Naturalis Historia, calling them: ‘The substance that possesses the greatest value, not only among the precious stones, but of all human possessions’

300 BC According to legends the Kohi-noor appeared two thousand years ago

1330

Diamond cutters believed to have first appeared in Venice sometime after this time. Venice was the diamond trading capital. By the late 1300’s the diamond trading route would go to Burges and Paris, then later, to Antwerp

500 “Ratnapariska,” a text on gems that summarizes India’s knowledge of diamonds, is written during this century. It describes the virtues and powers of diamonds, and how they were distributed among castes.

600 Isidore of Seville, a bishop and chronicler, said of the wedding ring, “It was given by the spouser to the espoused whether for a sign of mutual fidelity or still more to join their hearts to this pledge”

1375

First Diamond Cutter’s Guild is formed in Nurnberg, Germany

1475 The concept of creating absolute symmetry when cutting facets was introduced by Lodewyk Berken, Flemish stone-polisher from Antwerp, Belgium. Pear-cut diamonds emerge sometime after this event

1477 Roman Emperor Maximilian I gives a diamond betrothal ring to Mary the Duchess of Burgundy upon their marriage. This is an early example’ of a diamond wedding ring, and maybe the first royal example

13 D I A M O N D S T I MEL I N E

1499

Vasco Da Gama discovers a sea trade-route that directly links Europe with Indian diamond trading

1600

Jules Cardinal Mazarin, an Italian ambassador, he is credited with creating the first “brilliant cut” diamond.

1500 Bigger diamonds are being used. The “Rose” or “Rosette Cut” is invented; it remains popular for over a century

1600 Jules Cardinal Mazarin, an Italian ambassador, is credited with creating the first “brilliant cut” diamond

1800

Diamonds in jewelry become even more popular during this time. Diamonds are worn during the evening, since it was considered vulgar to wear them during the day

1900

Diamond saws and jewelry lathes are developed, leading to modern diamond cuts, including the popular “round brilliant” cut. A scientific understanding of diamonds and what causes their formation leads to diamonds being mined globally

1725

1867

1930

Major diamond sources discovered in Brazil

Discovery of diamonds in the Cape Colony, now a South African providence

The diamond became the main gem for wedding rings thanks to an impressive marketing by The Beers

1730 – 1870 Brazil is the largest producer of diamonds

1870 Around this time, diamonds from South Africa become so abundant that they are no longer only available to the upper classes

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indic a ting

ENGAGEMENT RINGS

w i v e s cu s to m , R o m a n a f ro m b e a uty a nd s tr e ngt h un m a tc h e d t h e ir o f b e c a u s e l o v e e nduring s igni f y

Diamonds signify steadfast, enduring love because of their unmatched strength and beauty. The versatile look of diamonds enables them to be worn with any outfit, from an elegant cocktail dress to blue jeans. It’s no wonder diamond engagement rings are the most popular accompaniment to popping the question. Although the tradition of giving a ring to the woman who has promised to become your bride goes back centuries, diamond engagement rings are a relatively recent innovation. Diamond engagement rings first became popular in the 1930s. By 1965, 80 percent of all new brides in the United States sported one. What’s the most important criterion for the diamond engagement ring? It should be a piece of jewelry that she loves and that fits within his budget. Find the style that best fits her personality with our fun, What Kind of Engagement Ring Should You Buy quiz. A man presents his prospective bride with an engagement ring upon acceptance of his marriage proposal. Anthropologists believe this tradition originated from a Roman custom in which wives wore rings attached to small keys, indicating their husbands’ ownership. In 1477, Archduke Maximillian of Austria commissioned the very first diamond engagement ring on record for his betrothed, Mary of Burgundy. This sparked a trend for diamond rings among European aristocracy and nobility. The sentimental Victorians popularized ornate engagement ring designs that mixed diamonds with other gemstones, precious metals and enamels. Often these rings were crafted in the shapes of flowers and were dubbed “posey rings.” Diamond rings crafted during the Edwardian era continued the tradition of pairing diamonds with other jewels, commonly mounted in filigree settings.

w or e

ring s

a tt a c h e d

Diamonds signify steadfast, enduring love because of their unmatched strength and beauty […] It’s no wonder diamond engagement rings are the most popular accompaniment to popping the question

D i a m ond s

DIAMONDS THROUGH TIME C.01

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DIAMONDS AND

It’s a result of Marketing

The secret to De Beers’ success is a marketing campaign that has permeated our culture—convincing every woman that she should receive a diamond ring from her fiancé and convincing each of the groomto-be to pay two-months salary for that ring to show how much his love is worth. Prior to the 1930s, diamond rings were rarely given as engagement rings. Opals, rubies, sapphires and turquoise were deemed much more exotic gems to give as tokens of one’s love, according to the book Twenty Ads that Shook the World by James Twitchell who also describes how De Beers changed the world diamond market. This idea of connecting diamonds to romance was captured in a brilliant ad campaign begun in the 1940s, causing demand for diamonds to increase. Surely you’ve heard the De Beers advertisement that A Diamond is Forever. This ad campaign, which was created by the N.W. Ayer advertising agency in 1947, transformed the diamond market. De Beers infiltrated Japan with the same ad campaign in the 1960s, and the Japanese public bought into the idea as much as the Americans did. Later ads by De Beers told consumers to hold onto their family’s diamond jewelry and to cherish it as heirlooms—and it worked. This eliminated the aftermarket for diamonds, which further enabled De Beers to control the market. Without people selling their diamonds back to jewelers or to other people, the demand for new diamonds increased.

There are fewer than 200 people or companies authorized to buy rough diamonds from De Beers. These people are called sightholders, and they purchase the diamonds through the Central Selling Organization (CSO), a subsidiary of De Beers that markets about 70 percent to 80 percent of the world’s diamonds. De Beers sells a parcel of rough diamonds to a sightholder, who in turn sends the diamonds to cutting facilities and then to distributors. Some rough diamonds are sold outside the Organization. These diamonds come from small producers in Australia, Russia and some African countries. The cost of diamonds is still largely influenced by the prices set by the it. Diamonds are the most coveted of all precious gems, as is witnessed by the extremely high demand for them. While this has not always been the case, diamonds are nonetheless exquisite gems that go through a long, tedious refining process from the time they are pulled from the ground to when you see them in the jewelry store. And, while some of the mystique of diamonds may be gone—they’re just carbon, after all, the diamond will likely continue to be a highly coveted jewel, because, well, A Diamond is Forever.But, as the saying goes, beauty often comes at a price. And, sometimes, that price goes beyond the financial realm. In the next section, we’ll examine some of the largest controversies in the diamond industry. In the end, after this massive marketing, De Beers changed the world diamond market.

D I AM O N D S A N D E N G A G EME N T R I N G S

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Prior to the 1930s, diamond rings were rarely given as engagement rings […] De Beers changed the world diamond market

Diamonds are a symbol of social status and economical success. However, it sometimes might bring misfortune and curses. One of the most famous case is the Hope Diamond.

chapter 02

Physical aspects of diamonds

PHYSICAL ASPECTS OF DIAMONDS

C.02

THE ROUGH CUT

PHYSICAL PROPERTIES

Diamonds are found as rough stones and must be processed to create a sparkling gem that is ready for purchase As mentioned before, diamonds are the crystallized form of carbon created under extreme heat and pressure. It's this same process that makes diamonds the hardest mineral we know of. A diamond ranks a 10 on the Mohs Hardness Scale. The Mohs Scale is used to determine the hardness of solids, especially minerals. It is named after the German mineralogist Friedrich Mohs. They can survive conditions that would destroy other materials and so they have many uses in science and industry. Natural diamonds are rare and very expensive so it hasn’t been possible to make full use of their amazing natural properties until recently. Now we have the ability to grow synthetic diamond crystals and wafers, opening up whole new worlds of technology. Researchers had determined diamonds from a crater in Arizona were formed by a meteorite. In addition to its size and heat, the meteorite had one other significant component: metal. Geogolist scientists reasoned that they could make diamonds using a smaller-scale meteorite crash in a laboratory. They combined carbon atoms with the liquid metal troilite and added heat and pressure. which results in the crystallization of diamonds. It is the molecular structure of diamonds that makes them so hard. Diamonds are made of carbon atoms linked together in a lattice structure. Each carbon atom shares electrons with four other carbon atoms, forming a tetrahedral unit. This tetrahedral bonding of five carbon atoms forms an incredibly strong molecule. Graphite, another form of carbon, isn’t as strong as diamond because the carbon atoms in graphite link together in rings, where each atom is only linked to one other atom. Another aspect to consider is the toughness of a diamond. This is slightly different from hardness, as it involves the ability of the diamond to resist breakage from heavy impact. Unlike hardness, the toughness of a naturally produced diamond is about standard—impressive to other types of gems but less durable than various materials used in engineering.

Material s hardnes s according to the m o h s m e a s u r e m e n t u n i t:

Ta l c E asily scratched by the fingernail

G y p s u m Just scratched by the fingernail

C a l c i t e S cratches and is scratched by a copper coin

F l u o r i t e N ot scratched by a copper coin and does not scratch glass

A pat i t e Just scratches glass and is easily scratched by a k nife

Q u a r t z [A met hys t , cit rine, t iger ’s- eye, aventurine] N ot scratched by a file

T o pa z S cratched only by corundum and diamond

C o r u n d u m [ S apphir es and rubies] S cratched only by a diamond

D i a m o n d S cratched only by another diamond

OPTICAL PROPERTIES

HIGH

LUSTER

T he high luster is a result of a diamond reflecting a high

HIGH

DISPERSION

A s white light passes through a diamond this high dispersion causes that light to separate into it s component colors

REf r a c t e d

c o l o r s

T he ideal diamond refract s the visual light spectrum, infrared and ultraviolet

Color, Dispersion & Reflectiveness

The visual appeal and characteristics of a gemstone are determined by several factors that include: brilliance or sparkle, color, fire or light dispersion, and luster or surface reflectiveness. A stone’s brilliance, fire, and to a lesser extent luster, are influenced by the type of cut and faceting that is employed. The faceting of a gemstone will affect how light will behave as it passes through the outside surface into the interior of the gem. Light can either be reflected off of the stone’s exterior surface affecting its luster; or the light can pass through the exterior surface of the stone and be refracted, scattered, and dispersed as the light bounces off of interior surfaces then exiting the stone. As a light beam passes through a gem it is bent or refracted before it exits the crystal. The light beam is also broken into its component parts dispersion causing the effect known as “fire.” The dispersion effect creates a rainbow of color, widening the beam of light to the point where the observer can see the full visible spectrum of the light-beam broken into its component parts; from red long wave to violet (short wave. As the stone is moved, the refraction and reflection points of the facets change, showing the stone’s scintillation or play of color.

O P T I C AL P R O PE R T I ES

percent age of the light that strikes it s sur face

C.02

PHYSICAL ASPECTS OF DIAMONDS

w HITE

LIGHT

w HITE

LIGHT

w HITE

LIGHT

THE ROUGH CUT

c RITICAL

ANGLE

d ISPERSED

c RITICAL

ANGLE

Faceting a Gemstone: The Critical Angle

The critical angle at which a light beam intersects with a given series of facets is the angle at which total internal reflection is achieved. Light traveling through the crown and interior of the stone will eventually intersect the outer surface of the stone’s pavilion facets from the inside. If the light intersects within the critical angle the facet will act like a mirror, and the light will exit, or return through the stone’s crown. If the light intersects outside of the critical angle of incidence it will be internally reflected and lost. The critical angle calculation is used to determine how facets should be placed in relation to each-other in order to control the path of light within a gemstone. In a properly faceted gemstone, the light should be reflected internally off the pavilion facets, and pass back through the crown facets light return to achieve maximum brilliance, sparkle and scintillation. The color of a gemstone, and the frequency (color) of the light traveling through it, can also effect its refractive index. On the other hand, the light path should not escape through the pavilion. When light passes from one density or type of material, air, into another, the gemstone, it is bent or refracted.

LIGHT

The amount, or degree, that the beam of light is bent will be determined by the density difference between the air and the gem. The measurement used to quantify the amount that a light beam is bent in a given material is known as its refractive index. There are two factors when calculating a gem’s refractive index: angle of incident and refractive angle. The incident angle is the angle of the approaching light as it intersects with the stone’s exterior surface. The refractive angle is the altered angle of the light as it passes through the stone’s interior. The refractive index is the ratio of difference between these two angles. The color of a gemstone, and the frequency of the light traveling through it, can also effect its refractive index. As the light’s frequency changes, so does its angle of refraction. Higher light frequencies travel through the stone more slowly, while lower frequencies travel faster, causing a spreading effect known as dispersion. As each frequency is reflected it is dispersed throughout the stone’s interior at varying speeds and directions. As the scattering and dispersion of light within the stone is increased, so to is the amount of “fire” that is returned to the viewer.

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O P T I C AL P R O PE R T I ES

23 t O O

When light passes from one density or type of material into another, it is bent or refracted. The amount, or degree, that the beam of light is bent will be determined by the density difference between the air and the gem. The measurement used to quantify the amount that a light beam is bent in a given material is known as its refractive index. There are two factors when calculating a gem’s refractive index: angle of incident and refractive angle. The incident angle is the light that approaches as it intersects with the stone’s exterior surface. The refractive angle is the one that the light as it passes through the stone’s interior. The refractive index is the ratio of difference between these two angles. Each material has its own unique density and refractive index. The color of a gemstone, and the frequency of the light traveling through it, can also effect its refractive index. Higher light frequencies travel through the stone more slowly, while lower frequencies travel faster, causing a spreading effect known as dispersion. As each frequency is reflected it is dispersed throughout the stone’s interior at varying speeds and directions. As the scattering and dispersion of light within the stone is increased, so to is the amount of “fire” that is returned to the viewer. The optical characteristics of a given transparent material is categorized as being either anisotropic or isotropic. In an isotropic material, the refractive index is uniform regardless of the light ray’s angle of incidence, meaning that the material exhibits no birefringence, and is singly refractive. Isotropic crystals that belong to very symmetrical crystal systems (ie. cubic or hexagonal) are singly refractive, and isotropic gems include: Cubic Zirconia, Diamond, Garnet, Opal and Spinel. Certain anisotropic crystals exhibit a phenomenon known as double refraction, where the incident light is split into two separate rays, each with different refractive indices and velocities, and their refractive indices will typically vary between two extreme values. Crystals belonging to asymmetrical crystal systems tend to have a higher occurrence of double refraction. Gemstones that are doubly refractive can exhibit pleochroism, dichrois.

PHYSICAL ASPECTS OF DIAMONDS

Start with Carbon

Carbon is one of the most common elements in the world and is one of the four essentials for the existence of life. Humans are more than 18 percent carbon. The air we breathe contains traces of carbon. When occurring in nature, carbon exists in three basic forms. Understanding the chemistry of a diamond requires a basic knowledge of the element carbon. A neutral carbon atom has 6 protons and 6 neutrons in its nucleus, balanced by 6 electrons. Diamond is made up of repeating units of carbon atoms joined to four other carbon atoms via the strongest chemical linkage, covalent bonds. Each carbon atom is in a rigid tetrahedral network where it is equidistant from its neighboring carbon atoms. The structural unit of diamond consists of 8 atoms, fundamentally arranged in a cube. This network is very stable and rigid, which is why diamonds are so very hard and have a high melting point.

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MOLECULAR STRUCTURE

Virtually all carbon on Earth comes from the stars. Studying the isotopic ratio of the carbon in a diamond makes it possible to trace the history of the carbon. For example, at the earthâ&#x20AC;&#x2122;s surface the ratio of isotopes carbon12 and carbon13 is slightly different from that of star dust. Each carbon atom joins four other carbon atoms in regular tetrahedrons triangular prisms. Also, certain biological processes actively sort carbon isotopes according to mass, so the isotopic ratio of carbon that has been in living things is different from that of the Earth or the stars. This network is very stable and rigid. Thus it is known that the carbon for most natural diamonds comes most recently from the mantle, but the carbon for a few diamonds is recycled carbon of microorganisms, formed into diamonds by the earthâ&#x20AC;&#x2122;s crust via plate tectonics. Some minute diamonds that are generated by meteorites are from carbon available at the site of impact; some diamond crystals within meteorites are still fresh from the stars.

T h r e e

c a r b o n

b a s i c

f o r m s :

D i a m o n d A n ex tremely hard, clear cr yst al T he electron shell configuration G r a p h i t e

A sof t, black mineral made of pure

of carbon is 1s 2 2s 2 2p 2 . C arbon has a valence of 4, since 4 electrons can be accepted to fill the 2p orbit al

carbon. T he molecular structure is not as compact as diamondâ&#x20AC;&#x2122;s, which makes it weaker than diamond.

F u l l e r i t e

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unit s of carbon atoms joined to four

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strongest chemical link age, it was

the covalent bonds

The crystal structure of a diamond is a face-centered cubic or FCC lattice. Each carbon atom joins four other carbon atoms in regular tetrahedrons triangular prisms. Based on the cubic form and its highly symmetrical arrangement of atoms, diamond crystals can develop into several different shapes, known as crystal habits. The most common crystal habit is the eight sided octahedron or diamond shape. Diamond crystals can also form cubes, dodecahedra, and combinations of these shapes. Except for two shape classes, these structures are manifestations of the cubic crystal system. One exception is the flat form called a macle, which is really a composite crystal, and the other exception is the class of etched crystals, which have rounded surfaces and may have elongated shapes. Real diamond crystals donâ&#x20AC;&#x2122;t have completely smooth faces, but may have raised or indented triangular growths called â&#x20AC;&#x2DC;trigonsâ&#x20AC;&#x2122;. Diamonds have perfect cleavage in four different directions, meaning a diamond will separate

neatly along these directions rather than break in a jag manner. The lines of cleavage result from the diamond crystal having fewer chemical bonds along the plane of its octahedral face than in other directions. Diamond cutters take advantage of lines of cleavage to facet gemstones. Graphite is only a few electron volts more stable than diamond, but the activation barrier for conversion requires almost as much energy as destroying the entire lattice and rebuilding it. Diamond crystals can also form cubes, dodecahedra, and combinations of these shapes. Therefore, once diamond is formed, it will not reconvert back to graphite because the barrier is too high. Diamonds are said to be metastable, since they are kinetically rather than thermodynamically stable. Under the high pressure and temperature conditions needed to form diamond its form is actually more stable than graphite, and so over millions of years carbonaceous deposits may slowly crystallize into diamond.

Diamonds are made of carbon atoms linked together in a lat tice structure. E ach carbon atom shares electrons with four other carbon atoms which forms a tetrahedral unit and the tetrahedral bonding of five carbon atoms forms an incredibly strong molecule.

M O LE C U LA R S T R U C T U R E

Crystal Structure

PHYSICAL ASPECTS OF DIAMONDS

C.02

THE ROUGH CUT

COLORS

E and F have no detectable color to the naked eye and they fall into the colorless category. Diamonds in the G to J color range have a hint of body color and are considered near colorless. The eye begins to detect faint traces of yellow in diamonds that are in the J to M range. Diamond ideals typically sells diamonds in the color range of D to J and occasionally K. The AGSL uses a slightly different color grading scale. The AGSL ranks the stones from 0–10, in 0.5 increments with 0 representing the equivalent of colorless d stones, and 10 representing the equivalent of X, Y and Z colored diamonds. Ideal cut diamonds offer a little flexibility in color selection. Because Ideal cut diamonds are designed to maximize brilliance and scintillation they also tend to mask subtle color differences making H and I color diamonds appear beautifully white. Ideal cut H and I color diamonds tend to appear whiter than poorly cut diamonds of the same color.

The most common diamond color is yellow. Most diamonds have a slight hint of yellow and the diamond color scale is based on the amount of yellow present in a diamond. These colors are classified according to the standards established by the GIA grading ccale. Grades are based on the amount of yellow that is visible when viewed facedown through the pavilion on a white diamond color card using daylight equivalent fluorescent light. Each color grade is based on a very small range. When a diamond is color graded it is compared using a set of master stones. Master stones are a set of real diamonds that display a range of known colors. It is extremely difficult to see the color differences within diamonds, but master stones help graders distinguish between one color and the next. As you can see the color-grading scale ranges from D to Z. The highest color grade and whitest stone available is a D color diamond. This is also the rarest color grade, which translates to a higher value. Colors

GIA

c o l o r

g r a d i n g

s c a l e

n e a r

C o l o r l e s s d

C o l o r l e s s h

F a i n t i

c o l o r l

W hile there are dif ferences in color bet ween

W hile cont aining traces of color, G to J

B eginning with K diamonds, color (usually yellow

D, E, and F diamonds, they can be detected only

diamonds are suit able for a platinum or white

tint ) is more easily detected by the naked eye.

by a gemologist in side by side comparisons,

gold set ting, which would normally betray any hint

S et in yellow gold, these warm colored diamonds

and rarely by the untrained eye. D – F diamonds

of the color in a diamond. B ecause I and J

appeal to some, and are an exceptional value. O thers will feel they have too much color. Due to

sh o uld o nl y b e in w hi te g o ld o r plat inum.

diamonds are more common than the higher grades,

Yellow gold reflects color, negating the diamond's

they tend to be a great value. A n I – J diamond

it s perceptible color tint, a K diamond t ype is

colorless ef fect.

may ret ail for half the price of a D diamond.

of ten half of the price of a G diamond.

V e r y

l i g h t

c o l o r

n – R

l i g h t

c o l o r

S – Z

Diamonds in the N – R color range have an easily

F or almost all customers, S –Z diamonds have

seen yellow or brown tint, but are much less expensive

too much color for a white diamond.

than higher grades

29 B r o w n ,

R e d

P i n k

D i a m o n d s

T hese diamonds owe their color to a combination of intense pressure and heat. T hese factors cause distor tions in the cr yst al lat tice that absorb green light, thus reflecting a pink hue. U ltra-rare red diamonds, which are essentially just deeply colored pink diamonds, have the same cause of color.

O r a n g e

a n d

Y e l l o w

D i a m o n d s

T he remark able hue of yellow and orange diamonds can be at tributed to one element: nitrogen. W hile a diamond is forming, nitrogen atoms will arrange in such a way that blue light is absor bed, therefore pro ducing a bright yellow color. A specific grouping of nitrogen atoms is also responsible for the shading of orange diamonds.

G r e e n

D i a m o n d s

I t is not until the last leg of their journey to the ear th’s sur face that diamonds get their green color. Just as they are about to leave the uppermost layer of the crust, these stones absorbs naturally occurring radiation, which causes them to reflect a green hue by absorbing red and yellow light.

G r ay

B l u e

D i a m o n d s

F or the most par t, blue diamonds get their color from boron. W hen this impurit y is present, it bonds to carbon in the cr yst al structure, absorbing red, yellow and green areas of the color spectrum.

V i o l e t

a n d

P u r p l e

D i a m o n d s

S o far, all scientist s are cer t ain of is that the cause of color for purple and violet diamonds is cr yst al distor tion. H owever, it is believed that the presence of hydrogen may be par tly responsible for their hue.

The traditional white diamonds or colorless diamonds that we all know about, such as those found in most classic engagement rings, pendants and other diamond jewelry, are created from a complex process involving super-heated, highly pressurized carbon molecules close to the Earth’s core. However, these are not the only diamond types out there. Natural Colored diamonds are created in the same fashion, with one unique difference. When foreign particulates are trapped during the crystallization process from which diamonds are formed, it effects and alters the chemical process and thus, changes the outcome. The result is a beautiful, rare, and exceptional diamond with unique colorings—called natural colored diamond. Colored diamonds come in as many hues and intensities as nature can possibly muster. The reason is not only can trace minerals influence color, but also variations in the amount of pressure exerted to produce the diamonds, as well as radiation levels in the Earth’s mantle layer can also influence diamond colors. In order to produce a particular hue, thousands of variables must be present in just the right amounts, at just the right times. Since scientists have never been able to observe a natural diamond being formed, the exact type and proportion of variables necessary are nearly impossible to determine. However, there are basics that have become understood. For example, boron produces natural blue diamonds, while hydrogen will produce violet and purple colored diamonds. Likewise, nitrogen in the right amounts will produce orange or yellow diamonds. Diamonds in the red to brown category have been scientifically proven to have an internal structure far more compressed than average white diamonds. According to the Natural Color Diamond Association, argyle diamonds show nearly ten times the amount of high pressure graining as more traditional diamonds. This graining is evidence of high-pressure conditions well above what it would take to form a white diamond.

COLORS

Fancy colors

PHYSICAL ASPECTS OF DIAMONDS

C.02

THE ROUGH CUT

CLARITY

The diamond's clarity is a description of its internal purity. With fewer imperfections within the stone, the diamond is more rare and has a higher value. The clarity scale was developed by the Gemological Institute of America to quantify these imperfections. The American Gem Society uses the same standards as the first. All diamonds are systematically graded and plotted under ten times magnification. If a trained grader cannot see a clarity characteristic, it does not affect the clarity grade. There are five factors that determine clarity which are taken into consideration when the analized diamond is assigned a clarity grade: size, number, position, nature, color. The exception to this is in Internally Flawless and Flawless diamonds, which take considerable examination to assign such high and valuable grade and it of course takes longer to plot included diamonds as well. There are two basic categories of clarity characteristics, inclusions, which are clarity characteristics that are completely enclosed in a polished gem or those extending into it from the surface, and blemishes, an external clarity characteristics caused by wear, and the cutting process or the diamonds crystal structure. Clarity enhancement is a treatment to improve a diamond’s apparent clarity. A diamond with eye visible inclusions can be seen as less desirable. To make the diamond more desirable and marketable, some sales people have the diamond clarity enhanced to make eye visible inclusions less visible or invisible to the naked eye.

INCLUSIONS

C r y s ta l

A nother mineral cr yst al cont ained in the diamond. T hese cr yst als can include other diamonds, garnet or a host of minerals

N e e d l e

A long, thin cr yst al

P i n p o i n t

A ver y tiny cr yst al that look s like a dot or speck of dust. Pinpoint s of ten congregate in clusters or clouds

T w i n n i n g

A series of pinpoint s, clusters or cr yst als that

w i s p

formed in a t winned diamond’s grow th plane

I n t e r n a l

T he appearance of faint lines, angles or

g r a i n i n g

cur ves caused by cr yst al grow th

F e at h e r

o r

A general term for any break or fracture in

g l e t z

a diamond

B e a r d e d

Minute feathers that ex tend from the girdle

g i r d l e

sur face into the stone

I n d e n t e d

T he original cr yst al sur face, or sk in, that dips

N at u r a l

below the polished diamond’s sur face

K n o t

A n included diamond cr yst al that ex tends to the sur face af ter polishing

C av i t y

S pace lef t when a sur face-reaching cr yst al comes out during polishing

BLE M ISHES

N i c k

A small chip -like characteristic

A b r a s i o n

S eries of minute nick s along a facet junction

S c r at c h

A thin, dull, white line across the diamond’s sur face

N at u r a l

Por tion of the original sk in that remains on the diamond

P i t

Small sur face characteristic that look s like a tiny dot

31 C LA R I T Y

GIA Clarity classification

vvs

Flawless

Internally Flawless

Very Very Slightly Included

Flawless diamonds have no inclusions also no blemishes when viewed under 10x magnification by a skilled grader. A diamond can have naturals confined to the width of the girdle, extra facets on the pavilion that are not visible face-up, laser inscriptions confined to the girdle and internal graining that is not white, colored or ref lective.

An IF diamond has no inclusions, only blemishes when viewed under 10x magnification.

These diamonds contain minute inclusions that are difficult for a skilled grader to see under 10x magnification. Typically V VS diamonds have a pinpoint or two; however, characteristics like a bearded girdle or tiny chips might also be in these diamonds depending on their visibility.

Very Slightly Included

Slightly Included

Included

Diamonds of VS clarity contain minor inclusions that range from difficult to somewhat easy to see under 10x magnification. Typical inclusions in VS diamonds include small crystals, feathers and distinct groups of pinpoints.

Diamonds of SI clarity contain noticeable inclusions that are easy (SI1) or very easy (SI2) to see under 10x magnification. Typical inclusions, such as crystals, clusters of pinpoints and feathers, are centrally located

Diamonds in the I clarity range contain inclusions that are obvious under 10x magnification. These inclusions can often be seen face-up without magnification, sometimes affect the stoneâ&#x20AC;&#x2122;s durability and can be so numerous or large that they affect the gemâ&#x20AC;&#x2122;s transparency and brilliance.

A diamond with natural flaws can be perfected. To make the diamond more desirable and marketable, some sales people have the diamond clarity artificially enhanced in order to make inclusions less visible or invisible to the naked eye.

chapter 03

Obtaining the diamonds

OBTA INING T HE DI A MONDS C.03

THE ROUGH CUT

MINING

Diamonds are formed from carbon crystallized by extreme pressures deep within the Earthâ&#x20AC;&#x2122;s mantle. Interestingly, they are also sometimes found at the site of a meteor impact. The conditions that forge diamonds over long periods of time underground also occur in the instant of impact between Earth and meteor. With technology advancement, scientists have also been able to create diamonds synthetically. Natural diamonds have been discovered in more than 35 countries. According to the US Geological Survey, the USGS, most of the known natural diamond reserves are located in Congo, Botswana, Australia, and South Africa. The Congo has the highest number of diamond reserves and is the leading producer of natural diamonds. Among the diamond producing countries, at least 15 also have the technology to produce synthetic diamonds, with the leading producers being Ireland, Japan, Russia, South Africa, and the United States. In addition to being sold commercially as gemstones for jewelry, diamonds are also used in the mining and construction industries as drill bits for machinery. Natural diamond accounts for about 12%

of all industrial diamond used, while synthetic diamond accounts for the remainder. World Industrial Diamond Reserves are estimated to be about 580 million carats, according to the USGS. Diamonds are generally mined in one of two ways, depending on the type of deposit. The most common is a primary deposit, usually occurring near a pipe, a volcanic pathway connecting Earthâ&#x20AC;&#x2122;s deep mantle to its surface. Diamonds are carried upward in these pipes, amid vast quantities of magma, in very forceful eruptions. If suspended in the magma for long periods of time, the diamonds can burn up or convert to graphite which is also formed by a carbon chain. To primary deposits, diamonds are also found in secondary or alluvial deposits. Like any other surface feature, diamond-bearing pipes are subject to natural weathering and erosion and, as the weathered and eroded material washes downhill and downstream, some eventually ends up in riverbeds or along the ocean shore near the mouths of a river. Initially washed into the shallow ocean by currents, these diamonds are pushed back along the shore by the ocean waves. Mining in the ocean generally involves

Open Pit Mining

Hard-Rock Diamond Mining

Open-pit diamond mining, also known as open cast mining is a method of extracting rock and minerals from the earth by removal from a machine-dug open pit or burrow. Open pit mines are typically used when mineral deposits are found close to the surface or along defined kimberlite pipes. Open pit mining is used when the surface material overburden covering the deposit is relatively thin and/or the desired minerals are embedded within structurally unstable earth cinder, gravel, or sand that is unsuitable for tunneling. Small pit lakes tend to form at the bottom of open-pit mines as a result of groundwater intrusion.

The term hard-rock mining refers to various techniques used to extract gems, minerals, and ore bodies that are in situ, and can only be accessed by tunneling underground and creating underground rooms or stopes that are supported by timber pillars or standing rock. Accessing the underground ore is achieved via a horizontal passageway called a decline, or a by a vertical shaft. A decline is a spiral corkscrew tunnel which circles the ore deposit, while a shaft is vertical tunnel used for ore haulage, running adjacent to the ore. A decline of it is typically used for mining personnel, machinery, and access to the ore.

infrastructure in place to enforce whatever environmental regulations may exist. In these regions, in addition to the human costs associated with conflict diamonds, the environmental toll of diamond mining operations can be steep pits are left open and loose fill is left unmanaged to runoff into rivers and streams, often with catastrophic effects. Besides being grossly underpaid, many diamond miners work in extremely dangerous conditions. Small-scale diamond mining is often conducted without training or expertise. Miners may lack safety equipment and the proper tools. They can easily die or be injured in landslides, mine collapses, and other accidents. Diamond mining also contributes to public health problems. The sex trade thrives in many diamond mining towns, leading to the spread of HIV and other sexually transmitted diseases. Environmental devastation resulting from diamond mining is another cause of disease. In Sierra Leone, miners have littered the landscape with thousands of abandoned mining pits. These pits fill with stagnant rainwater, become infested with mosquitoes, and serve as breeding grounds for malaria.

Placer Mining

Marine Mining

Artisanal Mining

Placer diamond mining, also known as sand bank mining is used for extracting diamonds and minerals from alluvial, eluvial, and or colluvial secondary deposits which is a derivative form of the open-cast mining used to extract minerals from the surface of the earth without the use of tunneling. Diamonds tend to concentrate in alluvial deposits in the same way that gold placers develop and gems are separated from waste material using various sifting and sorting techniques such as cone screens, box screens, or pans, which concentrate the heavier gems at the bottom, or sort material according to size.

Marine mining technology only became commercially viable in the early 1990s. The marine diamond mining employs both vertical and horizontal techniques to extract diamonds from offshore placer deposits, at a maximum depth of 500 feet. Vertical marine mining uses a six to seven meter diameter drill head to cut into the seabed and suck up the diamond bearing material from the sea bed. Horizontal mining uses of Seabed Crawlers remotely controlled, CAT-tracked underwater mining vehicles, move across the sea floor pumping gravel up to an offshore vessel. While on board, the gravels are separated and sorted into three sizes, with middle size being a candidate for final sorting.

Artisanal diamond mining, as known as small scale mining, involves nothing more that digging and sifting through mud or gravel river-bank alluvial deposits with bare hands, shovels, or large conical sieves. Laborers who work in artisanal diamond mining are called diamond diggers. Artisanal diamond production is a form of subsistence based non-mechanized mine that is used in poorer countries throughout the world. Artisanal diamond mining is used throughout west Africa, in conf lict zones where mechanized mining is impractical and unsafe.

MINING

building a wall to shield the area from surf, and bulldozing or pumping sand and other marine soil from above the diamond-bearing level. The most common and productive type of diamond mining, pipe mining, is a type of open-pit mining; therefore it involves similar techniques and environmental stresses as other types of open pit mining, in which large amounts of rock and materials, called overburden, are removed to allow access to the diamonds. Large areas of land and surrounding ecosystems can be disturbed as well as the potential for acid mine drainage causing damage to an ecosystem. Environmental reclamation surrounding diamond mining operations generally involves some effort to return the altered landscape back to its original shape. This includes not only saving the fill removed from the pit and refilling pits once mining has ceased, but also preserving topsoil to be re-deposited on reclaimed land so that vegetation can be planted. In addition, diamond mining faces challenges relating to energy use and emissions which can contribute to the global climate change. In certain parts of Sierra Leone and other diamond rich west African regions, there is little

15 0

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18 0

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C.03

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THE ROUGH CUT

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a m e r i c a

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Diamonds are found in alluvial deposits in diamond mines in places such as Botswana, Namibia, Canada, Brazil, Venezuela, Russia and Australia. The current leading nations in diamond production are still found in Africa, but other nations are beginning to produce diamonds in the volume in which African nations have been operating for the past century and a half. Three of the world’s leading diamond producing countries are in Africa: Botswana, Namibia and South Africa. The non-African leaders in diamond production include Canada, Brazil, Venezuela, Russia, and Australia. Canadian diamonds gained a strong foothold in the diamond trade when the politics met up with geology. As large diamond deposits were found in the Canadian Northwest Territories in the 1990s it was concurrently discovered that the nations of Sierre Leone, Angola and The Republic of Congo were using their diamond sales to fund civil war and blood diamonds. The branding of such diamonds as conflict diamonds gave the new Canadian mines the ethical upper-hand, and so it helped to bring the Canadian diamonds to the forefront of diamond the production. The Canadian diamond mining industry has strict regulations in place, documenting all of the diamonds produced from their mines. In this way these diamonds are assured of being Canadian diamonds, including having a polar bear mark inscribed on the diamonds in order to brand them. South America is also still producing diamonds in large quantities. Brazil and Venezuela are the two major diamond producing nations in this area. Newly available technology has allowed more and more diamond deposits to be mapped, giving this area the ability to remain strong in diamond production. The world leader of diamond production is still South Africa. For the past century and a half, South Africa has been the world leader in producing and transporting diamonds. It is through South Africa’s mass production, distribution and shrewd business decisions that they remain the world’s diamond leader. It is in South Africa that the diamond industry’s leader, De Beers is located. Through their ownership of the primary and largest diamond mines in the world, De Beers is able to control much of the diamond industry.

3 2

MINING

6 0

OBTA INING T HE DI A MONDS C.03

THE ROUGH CUT

SYNTHETIC DIAMONDS

For the synthetic manufacturers and the consumers, diamonds come down to a matter of time and money: days versus millions of years, thousands of dollars versus tens of thousands of dollars or more, while man-made diamonds sell for about 30 percent less than the natural ones

For people who can't afford real diamonds or want a 100 percent guarantee that their diamond is conflict-free, synthetic diamonds are a good substitute. For many years, the only synthetic option available was cubic zirconia, but now consumers can also choose from Moissanite and man-made diamonds. Cubic zirconia, commonly called CZ, is a laboratory gem that has been on the market since 1976. It's a hard gem, but it's not as hard as diamond. On the one hand, it is compositionally superior to diamond. The synthetic gem has greater brilliance and sparkle, it's entirely colorless and it has no inclusions. However, most consumers agree that it is simply too perfectâ&#x20AC;&#x201D;it looks artificial even to the naked eye. Because of this, some of its manufacturers have started producing the gem with colored tints and inclusions so that it more closely resembles diamond. Moissanite has become CZ largest synthetic rival. Moissanite became available in 1998, and it's even more similar to diamond in composition and appearance. Moissanite is harder than cubic zirconia, but at 9.5 on the Mohs Scale, it is still softer than diamond. Moissanite's color is faintly yellow or green, and the tint becomes more apparent in larger stones. It also has small, stretch-mark-like inclusions that form during its growing process. Like the cubic zirconias, Moissanite is more radiant than diamond, but this quality is considered a disadvantage rather than an advantage. The closest synthetic approximation to diamond is a man-made diamond. Unlike CZ and Moissanite, man-made diamonds are pure carbon. The Gemological Institute of America (GIA) recognizes these as real diamonds from a compositional perspective. But, the man-made diamonds donâ&#x20AC;&#x2122;t have the rich geological history that natural diamonds do. Laboratories simulate the heat and pressure from the Earthâ&#x20AC;&#x2122;s mantle that create natural diamonds. For the synthetic manufacturers and

S Y N T HE T I C D I AM O N D S

41 The synthetic gem has greater brilliance and spark le, it's entirely colorless and it has no inclusions. However, most consumers agree that it is simply too perfectâ&#x20AC;&#x201D;it looks artificial even to the naked eye.

the consumers, diamonds come down to a matter of time and money: days versus millions of years, thousands of dollars versus tens of thousands of dollars or more, while man-made diamonds sell for about 30 percent less than natural ones. If you want a uniquely colored, relatively inexpensive diamond (it will cost less than a natural colored diamond), you can find man-made ones in shades of orange, yellow, pink and blue. Finding a large diamond will prove a greater challengeâ&#x20AC;&#x201D;most man-made diamonds weigh less than one carat. If you want the best synthetic has to offer, man-made diamonds are a no brainer. Even jewelers can have a hard time telling them apart from natural ones. To prevent retailers from passing off man-made diamonds as natural ones, the GIA is selling machines that will help jewelers easily distinguish between the two. It may come as no surprise that the developer behind these machines is none other than the king of the natural diamond industry: De Beers. Lab created diamonds, also known as cultured diamonds, are grown in highly controlled laboratory environments using advanced technological processes that duplicate the conditions under which diamonds naturally develop in the earthâ&#x20AC;&#x2122;s crust. Once grown, cut and polished, these diamonds look identical to our natural conflict free diamonds, and are in fact chemically the same as diamonds obtained through mining. Our lab grown diamonds are now readily available in colorless ranges up to one carat. Cultured diamonds are also available in fancy colors that are considered very rare in nature, including popular hues of vivid fancy yellow. Fancy colored lab created diamonds sell at comparatively reasonable prices compared to their natural colored diamond counterparts. It is important to note the vast distinction between lab created diamonds and diamond simulants. Lab created diamonds are man-made diamonds that consist of actual carbon atoms arranged in the characteristic diamond crystal structure. Diamond simulants, such as cubic zirconia and moissanite, are diamond look-alikes and are not true carbon crystals.

Mining diamonds can vary from a small artisanal production to a large scale production. The latter utilizes big machines and trucks, removing big areas of earth causing irreparable damage to the environment.

chapter 04

Crafting a gemstone

M I N E S T O R E TA I L

THE ROUGH CUT

C.04

CRAFITING A GEMSTONE

T H E D I A M O N D J O U R N E Y: F R O M

Mining the Diamond Rough

Rough Reaches the Market

Rou g h ly 50% of d iamonds come f rom A f r ica , although some sources of diamonds have been discovered in India, Russia, Canada and Australia. The diamonds that made it to the surface were forced up volcanic activity, through kimberlite pipes. A typical pipe mine consists of a large vertical shaft and tunnels running from the main pipe. The deepest mine runs about 160 kilometers, down into the earth with hundreds of tons of rock, gravel and sand that need to be blasted, drilled, crushed and processed to yield just 27,000 kg mined annually. Only about 20% of all rough diamonds are suitable for polishing and the rest are used for industrial purposes. Once the rough is found, it is sold to the manufacturers.

A large proportion of the world’s rough supply goes to De Beers’ Central Selling Organization (CSO). The rough that the Central Selling Organization buys is sorted into more than 5,000 different categories. Once the rough is priced and sorted, it is then sold to manufacturers at sights and there are ten sights yearly, each lasting a week. The chosen few allowed the chance to purchase at these sights are called Sightholders. The balance of the world’s rough supply is sold to private buyers and through private auctions.

M INING

SORTING

Once diamonds are detected, there are dif ferent

Af ter processed at the mine, rough diamonds

t ypes of mining operation used to ex tract them

are delivered to sor ting exper t s to be sor ted

depending on the environment in which they are

and valued into dif ferent categories in

found. F ollowing ex traction

preparation for sale.

S i z e S h a p e Q u a l i t y C o l o r

47 T HE D I AM O N D J O U R N E Y

For hundreds of years, diamonds have fascinated man for its alluring sparkle and physical hardness exceeding all other gems.

Diamond Manufacturing

The Final Journey

Regardless of the source, all rough diamonds eventually end up at the cutting centers. Today, the major cutting centers are Israel, Antwerp, Bombay, Johannesburg, & New York. Upon reaching its destination the rough is carefully examined, nowadays with the help of computers, decisions are made on how it should be cut to yield the greatest value. After the stone’s size and shape are determined, taking into consideration the rough’s shape, as well as the quantity and position of its internal inclusions, the stone is marked and usually sawed. The stone then goes through a series of diamond cutters who each have their own specialty. Finally, the diamond is polished and cleaned, all ready for sale.

After the diamond is manufactured it needs to be sold but for decades, diamond manufacturers have sold their cut diamonds to jewelry manufacturers and wholesalers who in turn, sell to jewelry diamond dealers and to retail jewelry stores. Today’s Internet technology is changing the diamond market, diamond manufacturers now have a direct link to the final customer. Through the internet, it is possible to purchase the same quality diamond for a significantly lower price because it does away with the middleman.

CUTTING

AND

POLISHING

JEWELRY

M ANU F ACTURING

RETAILING

G em qualit y diamonds are usually distributed

W holesalers or manufacturers buy relatively

T he final st age of the diamond pipeline is

to one of the main diamond cut ting and trading

small amount s of unset, polished diamonds and

when diamond jewelr y is sold by ret ailers to

centers, where exper t s cut and polish the

sell these to jewelr y designers, manufacturers

the consumer.

rough diamonds into shapes

or ret ailers.

o f

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Angola Australia

E X PLORING T he gemstone of ten exist within k imberlite rock , which is a

Botswana

mineral lo c ated of ten beneath over burden. D iamond prospec tor s

Canada

who explore for these valuable mineral deposit s, of ten search for k imberlite by testing the ground for changes in magnetic fields.

Congo Namibia Russia

U d a c h n y Ya k u t i a , R u s s i a A r g y l e K i m b e r l e y, W e s t e r n A u s t r a l i a

M INING Once diamonds are detected, there are dif ferent t ypes of mining operation used to ex tract them depending on the environment in which they are found. F ollowing ex traction, the ore cont aining the rough diamonds goes through many st ages of crushing and processing before it can be sor ted and classified.

South Africa

Catoca Angola Venetia Musina, S outh Africa Jwaneng Botswana Orapa Francistown, Botswana Botuobinskaya Nyurba, Russia

SORTING

Size

A f ter processed at the mine, rough diamonds are delivered to sor ting exper t s to be sor ted and valued into dif ferent categories in preparation for sale. T here are thousands of dif ferent categories into which diamonds

Shape Qualit y

can be sor ted, dependent on size, shape, qualit y and color.

Color

CUTTING

Antwerp

AND

POLISHING

G em qualit y diamonds are usually distributed to one of the main diam o nd cu t t ing a nd t r ading c en ter s, w here ex p er t s, als o k n ow n a s diaman t aire s, cu t an d p olish t he ro ugh diamo nd s into sha p e s, such as the round brilliant, the oval, the pear, the hear t and the emerald.

Mumbai Te l A v i v N e w Yo r k

Polishing follows cut ting, before the diamonds are again classified

China

by their cut, color, clarit y and carat weight— also known as the ‘Four Cs’.

Thailand Johannesburg

Tif fany & co. Cartier JEWELRY

M ANU F ACTURING

W holesalers or manufacturers buy relatively small amount s of unset, polished diamonds. T hey sell these

Harr y Winston Piaget

to jewelr y designers, manufacturers or ret ailers.

Bvgari

Manufacturers produce diamond jewelr y designed and

Mikimoto

commissioned by a ret ailer or other jewelr y designers.

Graff Buccellati

RETAILING

United States 50%

T he final st age of the diamond pipeline is when diamond jewelr y

J a p a n 15 %

is sold by ret ailers to the consumer. T he value of diamond jewelr y sold

Italy 5%

each year is approximately U S $72 billion, which includes the cost of the diamonds, precious met als and other gems.

India 3% China 2% Other Countries 23%

T HE D I AM O N D J O U R N E Y

M i r o r M i r n y Ya k u t i a , R u s s i a

on l y f a ct , in v a l u e

v a l u a b l e ,

g e m s ton e a ny

con s id e r e d b e

o f a r e

to f l a w e d

d e p o s it s

h e a v i ly

di a m ond

too a r e

a l l o f 2 0 %

di a m ond s Mo s t b l a c k a n d g r ay g r e e n , b l u e , o r a n g e , r e d , p i n k , i n c l u d e c o l o r s

Some gemstones qualities can be identified in a first look at the stone. For example, the clarity grade of most diamonds is determined in less than two minutes.

roug h l y

Diamonds are judged on several factors that determine their beauty. Most diamonds never reach the consumer market because they are too flawed. Often, these diamonds are used for industrial purposes— as an abrasive, for drill bits or for cutting diamonds and other gems. If you've ever purchased a diamond, you've heard of the 4 C’s: clarity, carat, color and cut. The best quality diamonds, the more expensive; the most beautiful gemstones are used by the jewelry industry.

d i a m o n d

CRAFITING A GEMSTONE C.04

THE ROUGH CUT

THE 4C ’s

cut ’ ‘ p a s s ion t h e b y

f o l l o w e d

Carat Weight

Diamonds exhibit a strong sub-metallic adamantine luster. Though diamonds can be transparent to opaque, only transparent stones are faceted. Most diamonds are too heavily flawed to be considered valuable, in fact, only roughly 20% of all diamond deposits are of any gemstone value and still contain flaws and inclusions even if they are minute. A flawless diamond is exceptionally rare. Diamond clarity is graded on a scale that factors both size and visibility of flaws and inclusions, ranging from Flawless to large inclusions visible to the naked eye. Although the diamond clarity grading scale is considered official, an assigned clarity grade for any single specimen can vary tremendously depending on who did the evaluation or where the stone was evaluated. It is not uncommon for a single stone to be given two different clarity grades by two different labs.

The size of a Diamond is measured in carats. A carat is equivalent to 0.2 grams. Another weight measurement sometimes used for small for Diamonds is the point measurement. Each point is one/one hundredth of a carat. Diamonds, as well as other precious colored gemstones, are often sold together with a certification document that lists comprehensive details about the stone, especially their 4 C’s. These certificates are usually certified by recognized organizations such as the GIA and AGS, American Gem Society and provide authenticity on the purchased stone. Diamonds that are certified have a premium over non-certified stones.Diamonds are very difficult to synthesize, as their formation requires immensely high temperatures and pressure to form. However, the technology does exist to product synthetic Diamonds, but the output of these synthetic Diamonds is relatively limited due to the high costs involved in producing them.

Diamond Color

Diamond Cuts and Shapes

Diamonds are typically known to be colorless or white, but the most common colors are yellow and brown. Golden and brownish hues are owed to traces of nitrogen impurities. Brown and yellow diamonds are often referred to as champagne or cognac diamonds. Other diamond colors include pink, red, orange, blue, green, gray and black. Blue diamonds are colored by boron impurities, while other fancy colors are the result of irradiation and in some cases, crystal lattice defects. The official color grading system for colorless to low-saturation yellow and brown diamonds ranges in scale from D completely colorless to Z light-yellow. Fancy colors are graded on an entirely different scale.

The most prevalent cut for diamonds today is the brilliant cut, followed by the passion cut—both of which attempt to maximize a diamond’s brilliance and fire through precision faceting and proportioning. Modified brilliant cuts, step cuts and mixed cuts, such as rose cuts, are not as common as they once were in the past. The most popular diamond shape today is round. Other fancier shapes include pear, oval, radiant, princess or square, emerald or octagon, asscher, cushion, heart and trillion triangular shapes.

T HE 4 C ’ S

cut , ’ ‘ b ri l l i a nt t h e i s tod a y di a m ond s f or cut p r e v a l e nt m o s t T h e

Diamond Clarity and Luster

CRAFITING A GEMSTONE C.04

THE ROUGH CUT

THE CUTTING PROCESS

The Lapidaire

The Diamantaire

The word “lapidaire” which comes from the Latin word Lapis, is used in French for both the technique and the trade of cutting and shaping stones, precious or non-precious to create jewellery or art. The lapidaire is not involved in the actual cutting of diamonds, this work is only executed by the diamantaire, the density of diamonds requires a specific cutting method. In both cases, lapidaire and the diamantaire must turn a rough stone into the most beautiful stone, meaning the largest and purest stone, with the most profound and uniform color, and keep the amount of stone that is lost in the process to a minimum. The lapidaire is also a trador and merchant and often gemmologist, gemmology is the science that studies precious, semi-precious and decorative stones. In this profession it is necessary to have great knowledge of the material that is traded in order to be successful. There are different techniques for cutting colored stones, depending on the nature of the stones an the result the cutter wants to obtain. After this, small cracks and blemishes are taken of with a very fine polish. Facetting the stone is the most complex step in the process and requires a lot of experience: the stone is polished with the help of a device that consists of a rotating or vibrating disc. The final polishing, turning polish or with the help of vibrations, is done in order of taking of the sharp edges and to give the stone a finishing touch using diamond powder.

The first step of cutting a diamond is to examine the stone with great care. During this examination the diamantaire draws a plan for splitting the diamond and decides on the direction of the cut based upon the christalisation axis. Lines are drawn on the stone with ink to serve as guidelines for the following steps. The stone is then fixed in a wooden support which is also secured firmly in a vice. The diamantaire must choose the best cut for the rough diamond, based on the weight, clarity and color. Sometimes this is a difficult decision, because a diamond that is graded as excellent or very well cut can become more valuable than a diamond of more weight but less quality of cut. During the cutting process of it, a diamond looses 50– 6 0% of it’s initial weight.

01 T he stones are cut with the use of a small circular saw

02 T hey are reduced to a basic shape with small grinding stones that consist of discs set with diamonds

O b s e r vat i o n

55 Cleaving If the plannerâ&#x20AC;&#x2122;s decision is to cleave the stone, it then goes to the cleaver. Large diamonds are often pre-shaped by cleaving into pieces suitable for sawing. When the stone is very large and valuable, the cleaving is a most critical process, because a mistake by the planner or the cleaver can shatter the stone. The cleaver cuts a groove along the line showing where the stone is to be cleaved, using another diamond as a cutting tool. He mounts the diamond in a holder called a dop and inserts a steel wedge into the groove. He strikes the wedge sharply with a mallet and the diamond splits along its cleavage.

Nothing is harder than a diamond, therefore it cantnot be broken in pieces. Its crystals actually contain splitting lines along which chemical compounds are less strong than in other directions.

Sawing The third step, or second step if cleaving is unnecessary, in the diamond cutting process is sawing. The saw is a paper-thin disk of phosphor bronze, rotated on a horizontal spindle at about 4,000 revolutions per minute. The sawyer mounts the diamond in a dop and clamps it so that it rests on top of the blade. The rim of the saw is charged with diamond dust, and, as the sawing progresses, the blade continues to recharge itself with diamond from the crystal being cut. The saw will cut through a 1-carat rough diamond in four to eight hours, unless it strikes a knot, in which case it may take much longer than the original time.

Girdling The next step in cutting a round stone is called girdling. The diamond to be girdled is placed in the chuck of a lathe; while it spins, a second diamond mounted in a dop on the end of a lon

Faceting From the girdler the diamond goes to the lapper, or blocker, who specializes in placing the first 18 main facets on a brilliant-cut diamond. It then goes to the brillianteer, the worker who places and polishes the remaining 40 facets, if the stone is being cut in the standard 58-facet brilliant cut. Placing and polishing are done by setting the stone either in a lead dop or mechanical clamp and holding it down on a revolving cast-iron lap that has been charged with diamond dust. Great skill is necessary at every stage, but especially during faceting, because the angles of the facets must be exact in order to yield maxim um brilliancy, and their sizes must be accurately regulated to preserve symmetry.

T HE C U T T I N G P R O C ESS

Marking Marking is done after examining each rough diamond to decide how it should be cut to yield the greatest value. To make this decision, the shape of the rough diamond and the number and location of imperfections must be considered. Of utmost importance is the determination of the direction of the cleavage, or grain, in the diamond crystal because of its atomic structure, diamond can be cleaved in four directions parallel to the octahedron crystal faces. Taking these factors into account, the planner decides how the diamond should be cut and marks it to indicate where the stone should be cleaved or sawed.

CRAFITING A GEMSTONE

THE ROUGH CUT

C.04

TYPES OF CUTS

p oint

f r e nc h

ta b l e

b ri l l i a nt

b a gu e tt e

m irror

E m e r a l d

57 T Y PES O F C U T S ro s e

p e a r

s qu a r e

e m e r a l d

a s s c h e r

e uro p e a n

p rinc e s s

B I BL I O G R APH Y

THE ROUGH CUT

BIBLIOGRAPHY

Books

Rocks, Gems and Minerals Paul R. Shaffer, Herbert S. Zim, Raymond Perlman. Martin’s Press The Jeweler’s Directory of Gemstones Judith Crowe. DK Publishing Gem Identification Made Easy Antoinette L . Matlins, Antonio C. Bonanno. Gemstone Press Gems, Granites, and Gravels R. V. Dietrich, Brian J. Skinner. Cambridge University Press Gemstones Cally Hall. Simon & Schuster. Famous Diamond Ian Balfour. Antique Collectors Club Dist. Diamond: The History of a Cold-Blooded Love Affair. Matthew Hart Plume Press Diamonds Marijan Dundek Noble Gems Publications

Websites

Wuerzburg Uniaxial Minerals www.geographie.uni-wuerzburg.de NelsonIntroduction to Uniaxial Minerals. Stephen A. www.tulane.edu Refraction in Gems Stanford University www.stanford.edu The Art of Cutting Diamonds: The Manner of Preparing the Gems for the Market The New York Times http://query.nytimes.com/gst/abstract.html?res= 9F05E3DD1139E533A25754C0A96E9C94649FD7CF

About the Early Methods of Cleaving, Sawing, and Cutting Diamonds JJKent, Inc http://www.jjkent.com/articles/methods-cleaving-sawing-cuttingdiamonds.htm Optical Effects in Gems: Gemstone Refraction Index http://www.allaboutgemstones.com/gemstone_refractive_index.html What Creates the Color of Colored Diamonds? http://www.naturallycolored.com/diamond-education/how-arecolored-diamonds-made Learn about diamonds http://shop.diamondideals.com/education/find/four_cs.cfm

Blood Diamonds: Conf lict Diamonds-

Diamond Gemstone Information http://www.gemselect.com/gem-info/diamond/diamond-info.php

What is the Kimberley Process? Geology.com http://www.geology.com/articles/blood-diamonds.shtml

The Diamond Manufacturing Process https://www.diamondonnet.com/knowledge/index.php

Bushmeat The Animal Welfare Institute http://209.85.165.104/search?q=cache:Sb2nf0kvVlUJ:www.awionline. org/ othercampaigns/Bushmeat/bushmeat.pdf+Bushmeat+the+taste +of+extinction&hl=en&ct=clnk&cd=2&gl=us Conf lict Diamonds United Nations Department of Public Information http://www.un.org/peace/africa/Diamond.html Cubic Zirconia Estate Antique Jewelry Sarasota Gold and Silve http://www.sarasotagoldandsilver.com/info/Cubic_zirconia.php A Diamondâ&#x20AC;&#x2122;s Journey Hussain, Sakina Sadat and Peter Cahil http://www.msnbc.msn.com/id/15842546/1 The Precious Gemstone Diamond http://www.minerals.net/gemstone/diamond_ gemstone.aspx Diamond Geology.com http://geology.com/minerals/diamond.shtml

From rough diamond to cut diamond http://www.private-diamond-club.com/rough-diamond-cut-diamond A History Of Diamond Cutting http://www.langantiques.com/university/index.php/A_History _Of _ Diamond_Cutting GIA 4cs education Gemological Institute of America http://www.4cs.gia.edu/en-us/diamond-color.htm How Diamonds Work by Kevin Bonsor http://science.howstuffworks.com/environmental/earth/geology/ diamond4.htm

The worldâ&#x20AC;&#x2122;s top 10 biggest diamond mines http://www.mining-technology.com/features/feature-the-worlds-top10-biggest-diamond-mines/

Typefaces Kepler Light Subhead as bodytext; AkzidenzGrotesk Medium as main titles; Helvetica Neue Bold and Light for small captions Software Adobe InDesign CS6; Adobe Illustrator CS6; Adobe Photoshop CS6 Equipment Asus X550J Windows 8 Epson Artisan 1430 Wide Format Inkjet Printer Paper Red river 50lb, white Publisher Taschen, Cologne, Germany Designer Evelyn Furuta Photography and Illustration Sources: various Editing: Evelyn Furuta About the project This book is a student work. Any part of this book and any deliverable for this project were NOT produced for commercial purposes.

The Rough Cut Diamonds, long revered as the most prestigious and desired of gemstones, are valued far beyond their beautiful aesthetic alone. This book examines their unique qualities and how they influenced society throughout history.