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Quartz
Mohs hardness 7 – lower in impure varieties, Specific gravity 2.65; variable 2.59–2.63 in impure varieties, Refractive index 1.543–1.545 Quartz is the second most abundant mineral in the Earth's continental crust, after feldspar. There are many different varieties of quartz, several of which are semi-precious gemstones. Especially in Europe and the Middle East, varieties of quartz have been since antiquity the most commonly used minerals in the making of jewelry and hardstone carvings. The word quartz is derived from the German word "quarz", which was imported from Middle High German, "twarc". Quartz belongs to the trigonal crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end. In nature quartz crystals are often twinned, distorted, or so intergrown with adjacent crystals of quartz or other minerals. Quartz is the material identified as the mystical substance maban in Australian Aboriginal mythology. It is found regularly in passage tomb cemeteries in Europe. The Irish word for quartz is grian cloch, which means 'stone of the sun'. Roman naturalist Pliny the Elder believed quartz to be water ice, permanently frozen after great lengths of time. The word "crystal" comes from the Greek word "ice".) He supported this idea by saying that quartz is found near glaciers in the Alps, but not on volcanic mountains, and that large quartz crystals were fashioned into spheres to cool the hands. He also knew of the ability of quartz to split light into a spectrum.
PRASIOLITE - A green member of the Quartz clan. Inspires self-reliance and originality. Gives us the courage to dare new things.
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