Montana is filled with many minerals. One of the most intriguingly named is dogtooth calcite. Not, in fact, a fossil of actual canine teeth, “dogtooth” is actually a reference to the shape of the crystals: the golden honey-colored calcite naturally forms into very pointy pyramid shapes. At times, the crystals will double terminate, creating beautifully faceted footballs.
BOZEMAN EDITION
in polarizing microscopes; and it was also utilized in experiments to refract light in ways that appear to produce a “cloak of invisibility.”
The Monthly
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Calcite is a soft mineral that is easily scratched with a knife. Found in more different shapes than any other mineral, calcite is sedimentary and has perfect cleavage. In addition to the desired golden honey of the dogtooth crystals, calcite also comes in clear, black, grey, white, blue, pink, brown, yellow and red. Both fluorescent and phosphorescent, calcite is also the mineral that has preserved trilobites’ detailed compound eyes for us to admire.
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Calcite is a wonderful mineral to start collecting or to add to an existing collection. It is as beautiful as it is fun. The added thrill of potentially finding your own piece here in Montana increases its desirability. Earth’s Treasures has many other minerals to excite
September 2014
The More Things Change, IN THIS ISSUE Page 3 The More They Stay The Same Iceland spar, another type of Montana calcite, forms in a rhombohedrum shape (picture a box that has been slightly squished and tilted to one side). The most sought after of this type is clear and referred to as optical calcite. This calcite is strongly double refractive, meaning that if a square-ish piece of optical calcite is laid on top of a straight line or image, the viewer will see two separate images. This happens because the calcite splits one ray of light into two separate rays. One remains stationary, while the other can revolve around the stationary ray. As the piece of calcite is turned a quarter turn, the lines will recombine into one line; another quarterF11 turn, and the two lines reappear. Besides being entertaining, this capability made optical calcite valuable in several applications: In World War
By Dave Berghold, Owner of The Last Wind-Up
Earth's Treasures
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novice rockhounds and serious collectors. For more information, please call 586-3451 visit EarthsTreasuresMT.com or come in to Autumn Adventures the shop at 25 N. Willson and browse throu our collection of remarkable treasures from around the world.
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Verge Theatre Occasionally, I'm asked: “Do people still wear pocket watches?” My response is always a resounding, “Absolutely!” That watch just comes in a different case that also happens to include a phone, email and apps. When pocket watches first appeared, they were suspended from a belt or sash by a chord or metal chatelaine (chain) outside of the pocket. Though they did tell the time, they were mostly a status symbol afforded only by the very wealthy. As time passed, these mechanical wonders became smaller and were fitted with new complications, or features, such as the date and phases of the moon. Some would strike the time at the top of the hour (clock-watch), while others would strike when the owner pressed a button on the side of the case (a repeater). Still others were used to track short lapses of time, as in a horse race (a chronograph). These were the 18th, 19th and 20th century “apps” for a watch. With the advent of mass production and interchangeable parts, the watch became more cost-effective, enabling the average person to have independence with a personal timepiece. Even women wore watches, as pendants on long chains
tucked into a skirt or blouse pocket or, later, as a bracelet, an early and timeless fashion statement. For men, the pocket watch reigned until WWI, when preferences changed to wristwatches for accessibility and convenience sake, particularly for troops. In the wake of the war came growth in a range of industries and interests, including timekeeping. New materials allowed for watches to be almost completely anti-magnetic, improving their accuracy dramatically. Watches were developed that could be plunged to the depths of the ocean or withstand great impacts of shock. In the mid 1920s, Henry Graves commissioned Patek Philippe, the Swiss premier watchmaker, to make the world’s most complicated watch. Eight years later, the watch was (continued on page 10)
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