Amethyst

General Information

Amethyst is the beautiful violet-purple variety of quartz, and is one of the most popular and well-known gemstones. It is found in a wide range of shades appealing to many different markets and tastes, from pretty pale lilacs to gorgeous, deep purples. Amethyst may occur as clusters of crystals that are colourless at the base and shading to deep purple at the tips, or as very large, perfectly formed single crystals. There is a magnificent amethyst in the Sceptre of the Cross in the Crown Jewels of Britain

Pure quartz is colourless; the name amethyst comes from the Greek amethustos, meaning ‘not drunken’, as it is believed that if one drinks from a cup of amethyst, one will not become inebriated.

Quality

As with any gemstone, amethyst quality varies from the very high to the very low. Deep purple Amethyst with a slight reddish tint is the most valuable material, and lighter shades tend to be less costly.

Treatment

Heat – Amethyst may be heat treated to improve the intensity of the colour, and this process is permanent and stable. Untreated stones that are also bright and clean are highly prized and always cost more than a heated stone of similar appearance.

Folklore

Amethyst is traditionally the birthstone for February. Amethyst has long had the reputation of resisting drunkenness, courtesy of Greek mythology. The colour purple, and therefore amethyst, has long been associated with royalty and nobility, and is a symbol of higher intellect. The dedicated stone of St Valentine, he was said to wear an amethyst ring depicting cupid. Wearing an amethyst can help a woman retain the affections of her man, as it signifies true, deep love.

Care

As a variety of quartz, amethyst is fairly resilient and suitable for normal wear, while being slightly brittle. Care should be taken not to knock the stone, as it may chip, particularly along facet edges and the girdle. Use judgement before cleaning in an ultrasonic. Amethyst may fade after prolonged exposure to bright light or extreme heat (e.g. jeweller’s torch)

Scientific Information

Chemical Composition     SiO₂ (Silicon Dioxide)

Crystal System                Trigonal

Refractive Index              1.544 - 1.533

Specific Gravity                2.65 - 2.66

Hardness                         7

Cleavage                         None

Fracture                           Conchoidal

Lustre                              Vitreous