Amethyst
Purple variety of quartz
Quartz is the reference stone for hardness 7 on Mohs´ scale of hardness
Origin of name: greek.: a methıein, to be not intoxicated
According to popular belief amethyst protects its bearer from drunkenness
Synonyms and trade names: Bishop´s stone
Can be confused with: Almandine and Rhodolite Garnet, purple Sapphire, purple Spinel, purple Tourmaline, Kunzite, glass and synthetic Amethyst
Localities: common worldwide, the commercially most important sources are located in South America (Brazil, in the past also Uruguay) and Africa (Zambia).

Amethysts from Brazil


Amethysts from Kalomo, Zambia
Amethyst "Rose de France" colour, Brazil

Amethyst with Lepidocrocite inclusions, Brazi
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Handling: Amethysts change colour to yellow or brownish-yellow to brown if heated. Be careful during soldering as colour change can occur at relatively low temperatures.
Sensitive to hydrofluoric acid only.
Amethyst has no or only very weak cleavage and thus is unproblematic during setting.
Worth knowing: Amethyst crystals often sport distinct colour zoning which poses a challenge to the gemcutter. In skilfully facetted stones the zoning is only visible when viewed from the side. When viewed from the top, colour should appear distributed evenly. In most cases zoning will be nearly to completely invisible in a bezel setting.
Attention: the market is flooded with synthetic Amethysts which are very hard to identify. Be particularly alert with intensely coloured eyeclean stones. The presence of colour zoning is not (any more) proof of natural origin

Synthetic Amethysts
We buy eyeclean stones only from reliable suppliers - well, actually we, of course, buy all our stones from reliable sources only ;-) - and only if we get a chance to inspect the rough material ourselves. No matter if we order from a factory or give our own rough for cutting, our local agents monitor the whole cutting process.
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Gemmological Properties of Amethyst |
| Formula | SiO2 |
| Crystal system | trigonal |
| Mohs hardness | 7 (reference stone) |
| Specific gravity | 2.65 |
| Refractive index | birefringent 1.543-1.554 |
| Max. Birefringence | 0,009 |
| Dispersion | 0,013 |
| Pleochroism | none or weak bluish purple to reddish purple |
| Luminiscence | inert |
| Lustre | vitreous |
| Cleavage | weak |
| Fracture | conchoidal |
| Colour | almost colourless to deep purple |
| Spectrum | sdfsdf |
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