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February is Amethyst by Harry W. Short Engineering Geologist February’s birthstone is a purple to violet crystalline form of quartz composed of silica and oxygen. Amethyst’s color may have originated from small concentra- tions of manganese present during forma- tion. When amethyst is exposed to heat it becomes colorless; however, the color returns with a smoky hue when subjected to radiation. The name comes from the Greek word amethustos meaning “not drunken.” An amethyst jewel placed in a wine goblet filled with water gave it a purple coloration and thus was a remedy for drunkenness. The ancient Anglo-Saxons made beads from amethyst. When worn in battle as an amulet during the Middle Ages, the stone was thought to protect soldiers from injury. Royalty held the amethyst in high regard. Edward the Confessor, who became King in 1042, first wore an amethyst gem in the British Crown. This is likely the oldest gemstone in the British Crown Jewel collection. In the 18th century, amethyst was considered to be as valuable as diamonds. Queen Charlotte of England had an amethyst necklace valued at $10,000. Rings worn by the popes and cardinals have amethyst gems and are considered sacred. Amethyst is found in geodes, on the walls in cavities, or as veins in granite and other igneous rocks. It’s a valuable gemstone due to its deep, uniform color. Without its characteristic color, the gem will be nearly colorless and looks like clear quartz. Large crystals for gem purposes are generally rare because the color is not uniformly dispersed through the crystal. Large crystals are used for study in geology classes or displayed by collectors and in museums. Amethyst crystallizes with six sides in the hexagonal system with pyramids on each end terminating in a sharp point unless it occurs in a mass of crystals. Its hardness is 7.0; specific gravity is 2.6 and has a conchoidal fracture. The purple crystals are easily identified because of their shiny luster and hexagonal shape. Good gem-quality amethyst is transparent to subtranslucent and should have no fractures or inclusions. It is believed the early European am- ethyst came from Russia. However, the gemstone has also been mined in Brazil, Uruguay, India, SouthAfrica, and Sri Lanka. In the United States, amethyst has been found in Texas, Delaware, Pennsylvania, North Carolina, Maine, and Yellowstone National Park. At one time, beautiful am- ethyst crystals were collected in rock along the north shore of Lake Superior. Harry Harry Short may be contacted via e-mail to michele@ worldwidedrillingresource.com Amethyst crystal photo by Chip Clark. 8 $04(-& 2'$ #0(++(-& (-#31207 1(-"$ 9 8 '$- (2 ".,$1 2. : ; 5$ *-.5 2'$ 9 $12 0!-*%.02 ++(-.(1 ."!2(.- ,!(+ 2$$)!7 ,(#5$12 -$2 !6 .++ 0$$ 0$2(/ %.0 12 FEBRUARY 2016 WorldWide Drilling Resource ®