Amethyst
Amethyst is a variety of crystallized quartz ranging in colour from light purple (mauve) to a stunning deep purple with bright blue, violet, magenta or red flashes.
The name comes from the Greek word 'Amethystos' meaning 'a remedy for drunkenness'. The Greeks and Romans sculpted drinking vessels out of amethyst quartz and wore amethyst amulets and rings, in their belief that it would prevent alcoholic intoxication.
Amethyst has long been associated with Christianity; bishops of the Catholic Church wore rings set with amethyst and it featured strongly in church ornaments.
It is a very popular and reasonably priced gemstone, although very cheap stones are likely to be synthetic amethyst (manufactured) or imitations (glass or other dyed material).
There are many source locations for amethyst, the list includes: Africa (Zambia and Namibia), Brazil, Burma, Canada, Europe (Germany and Italy), India, Madagascar, Mexico, Russia, Sri Lanka Uruguay and USA (Arizona, Colorado, North Carolina). High quality stones can be found in many parts of the world: Siberia, Brazil and Uruguay supply some of the best quality amethyst.
Properties of the Gemstone and Additional Information
| Gemstone type: | Amethyst is a variety of crystalline quartz |
| Crystal System: | Trigonal (hexagonal) Crystals occur as hexagonal prisms |
| Chemical Composition: | Silicon dioxide - SiO2 |
| Colour: | Light to dark purple |
| Lustre: | Vitreous |
| Pleochroism: | Weak variation in violet colour, seen as violet-grey and violet-red |
| Dispersion: | Low |
| Hardness: | 7 on the Mohs' scale |
| Toughness: | Good |
| Cleavage: | None |
| Density in gm/cc: | 2.65 |
| Double refraction: | Yes |
| Refractive index: | 1.544 to 1.553 |
Common Treatments
Some amethysts are produced by irradiating clear and smokey quartz. Heat treatment is also used to lighten dark amethyst.