Amethyst Tumbled Stone

Amethyst is the violet variety of quartz. SiO₂. Trigonal crystal system. Mohs hardness 7. The colour comes from iron held in the quartz lattice, worked on by natural radiation over geological time - colour centres that give the stone its range from faint lilac to near-black purple.

It forms in gas cavities within volcanic basalt. The great Brazilian and Uruguayan geodes grew inside cooling lava flows of the Paraná province, around 130 million years old; silica-rich water deposited quartz on the cavity walls, and the colour deepened toward the crystal tips. The colour is often zoned for exactly this reason.

A note on citrine: most commercial citrine on the market is heat-treated amethyst, turned yellow to orange in a kiln. The amethyst here is untreated - the colour is the one the stone grew with.

Asked often

Is the amethyst genuine and untreated?
Yes. The colour is the one the stone grew with - not dyed, not heat-altered. Most commercial citrine is heat-treated amethyst; this is left as it was found.

Why is the colour uneven across the stone?
Amethyst grows with its colour zoned, deepest toward the crystal tips - so a cut pyramid often deepens toward the apex. The variation is the stone itself, not a fault.

Will the colour fade?
Prolonged strong sunlight can pale amethyst over time. Set it out of direct sun and the colour holds.

How do I look after them?
Wipe with a soft cloth. Hard-wearing at Mohs 7; rest them out of prolonged strong sun, which can pale the purple.

1. Carried in a pocket or a bag, or held in the hand.
2. Kept in a small dish, on a desk, or on a shelf - each stone is a little different.
3. Wipe with a soft cloth; rest them out of strong sun, which can pale the purple over time.

Each stone is tumble-polished and unique, so a set varies a little stone to stone. Many keep a stone where they will see it each day, or carry one in a pocket; that is a matter of preference.

Pocket stones to keep and carry. Wipe with a soft cloth and rest them out of prolonged strong sun, which can pale the colour. Hard-wearing at Mohs 7.

• Stone: Amethyst · violet quartz
• Hardness: Mohs 7
• Character: Pale lilac to deep violet · often zoned
• Treatment: None · untreated
• Form: Tumbled stones · polished, each unique · sold in a set
• Origin: Brazil
• Care: Wipe with a soft cloth · rest out of strong sun

For most of history amethyst was rare and dear - its deep violet among the hardest colours to find in a clear, hard stone. The peoples of Egypt set it into gold, and Greece and Rome cut it into rings and seals; the colour was prized as one of the great tones a gem could carry.

It was one of the cardinal gems of antiquity, set into the most important jewellery of Greece, Rome, and later Europe, and named by Pliny in the first century. For most of that history Europe’s amethyst came from Russia and Germany; the great Brazilian supply arrived only in the nineteenth century. What the stone has meant to the people who carried it is theirs, and now yours, to decide.