Amethyst, that wonderful pale lilac to deep reddish purple variety of quartz, occur in vesicles in volcanic rocks as well as pegmatite and hydrothermal veins.
Its occurrence is vast, across much of the world. From Siberia to Europe, South America, Asia and Africa. Principal sources are Minais Gerais (Brazil), Zambia and South Korea. You can even find amethyst in the UK. Look for water worn pebbles on Scottish and Cornish beaches.
The name is derived from the Greek amethystos, meaning ‘not drunken’. It was believed that it protected the wearer from drunkenness. In mythology Dionysus sought revenge on mankind for an insult he had received. A young maiden, called Amethystos, became his intended victim. Dionysus created tigers to carry out the deed but Artemis intervened by turning Amethystos into a white quartz stone. Dionysus wept on seeing the beautiful statue, his wine charged tears turning the stone purple.
By coincidence some amethysts contain healed fractures called ‘tiger stripes’.
It was favoured by the clergy, roman emperors and medieval soldiers who believed that wearing an amethyst would enable them to remain cool headed.
Amethysts other attributes include piety, humour and wit. It is said to sharpen the mind and protect the wearer against magic.
The Science
Amethyst is a crystalline variety of quartz. Silicon dioxide, owing its colour to manganese.
Crystal system: Trigonal
Hardness: 7
Specific gravity: 2.65
Refractive index: 1.544 to 1.553
Birefringence: 0.009
Can be heated to light yellow, reddish brown, green or colourless.
The light yellow heat treated type that resembles the quartz variety citrine does not exhibit pleochroism, whereas true citrine does.
Want to learn more about Amethyst? Then visit the Gemmological Association of Great Britain website for available courses www.gem-a.com
Steven Jordan FGA DGA FIRV FNAJ
Fellow of the National Association of Jewellers Institute of Registered Valuers
For jewellery and silver valuations: steven@blog.hawksworth-valuations.co.uk
