Amethyst

Purple variety of quartz
Quartz is the reference stone for hardness 7 on Mohs´ scale of hardness

Amethyst shop

Origin of name:
greek.: a methýein, 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).

 



amethyst aus brasilien amethyst aus brasilien

Amethysts from Brazil


Amethyst aus Kalomo, SambiaAmethyst aus Kalomo, Sambia

Amethysts from Kalomo, Zambia


Amethyst Rose de France        
Amethyst "Rose de France" colour, Brazil


Amethyst mit Lepidokrokit Einschluessen
Amethyst with Lepidocrocite inclusions, Brazil


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


Amethyst synthetisch       Amethyst synthetisch

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.

Amethyst shop

 

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:
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