Why are diamonds ‘rare’?

from Sixer August 2023

The Diary

f diamonds are available in every jewellery shop, how can they be rare? We are often asked this question and it is not the most straightforward to answer. In part this is because whether something is rare or not depends on how you define that concept.

There are many gemstones that are far rarer than diamond; an oft-cited example is Tanzanite, regularly marketed as ’1,000 times rarer than diamond’. It is found in only one location on earth whereas diamond is mined in many countries around the world. Diamond is not absolutely rare in the way that Tanzanite is. Its rarity is more complex…

Diamond is formed of carbon, a common element. However, the conditions required for carbon atoms to form as diamond only exist naturally at the incredible pressures and temperatures found deep within the earth’s mantle. At the surface carbon exists as graphite – familiar as the ‘lead’ in pencils.

Research suggests there may be vast quantities of diamond in the mantle and some argue that this makes diamond ‘common’, but I would disagree since these stones aren’t accessible: we can only mine diamonds that have been brought to the earth’s surface by volcanic activity and survived the brutal journey. The areas of the mantle where diamonds are most likely to form are also areas that see little volcanic activity, so many never reach the surface and remain out of reach.

Diamonds are mined are in some of earth’s most challenging terrains, as varied as the perma-frost of northern Canada and the desert beaches of Namibia. Mining in these environments is expensive, requiring intensive investment in infrastructure and equipment. A huge amount of rock must be excavated, crushed and processed to recover a handful of diamonds.

Around two-thirds of diamonds mined are only of industrial quality, unsuitable for jewellery (diamond has a range of industrial applications due to its extreme hardness). The remainder will still vary greatly in size and quality; large stones with good colour and clarity make up only a tiny fraction. This is where a more nuanced idea of rarity comes in; the balance between small supply and high demand for fine diamonds means that they are rare. Essentially, the larger the stone, the more difficult it becomes to achieve a fine colour and clarity and present a scintillating white sparkle.

For such pure and beautiful diamonds to form, survive the journey from the earth’s mantle, be recovered and fashioned to make it into your piece of jewellery is really one of nature’s most brilliant wonders!

Our showroom is staffed with qualified gemmologists and diamond graders. We are happy to answer any questions you may have about diamonds and talk you through the factors that affect diamond pricing. Just call in to our showroom for a chat.

PA Jewellery

The Old Bank, 23 Commonside, Sheffield, S10 1GD Tel: 0114 266 9253 www.pajewellery.com