Description
A clear, purple, quartz gemstone that have been gathered or mined since Neolithic times. Sources for amethysts include Germany (Idar-Oberstein, now delpleted), Ural Mountains, India, Sri Lanka, Egypt, Siberia, Brazil, Uruguay, Zambia (since early 1980s), Canada (Ontario, Nova Scotia), and the U.S.(Michigan, Virginia, Montana, Maine). The purple color of amethyst is due to trace impurities of iron and manganese. Amethysts crystals are doubly refractive. The crystals are used for jewelry, pivot bearings in instruments, and recording needles. Oriental amethysts are purple corundum. Amethystine quartz is an amethyst streaked with bands of milky quartz.
Synonyms and Related Terms
quartz; amethystine quartz; Siberian amethyst(dark purple); rose-of France amethyst(pale purple to pink); Amethyst (Deut.); amatista (Esp.,); améthyste (Fr.); amethist (Ned.); ametyst (Pol.); ametista (Port.); ametist (Sven.)
| SiO2 |
| 7.0 |
| 2.65-2.66 |
| 1.544-1.553 |
Other Properties
Color=reddish purple in tungsten and bluish violet in daylight or fluorescent; Natural aquamarine is almost always color-banded; Turns to dull yellow/green with heat.
Trigonal crystal system. Low birefringence. Low thermal expansion.
Fracture = conchoidal. Luster = vitreous to greasy. Streak = white.
Additional Information
° Mineralogy Database: Quartz
° Michael O'Donoghue and Louise Joyner, Identification of Gemstones, Butterworth-Heinemann, Oxford, 2003
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Last updated on: 7/2/2009 10:42:08 AM
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