Occurring in shades of violet, purple, lilac, and mauve, amethyst is the most valuable stone in the quartz group. Some Amethyst stones are heat treated to produce the yellow stone citrine. Amethyst is traditionally thought to be a strong talismanic stone, and it's crystals are still used in various forms of alternative medicine.

Amethysts were thought to induce a sober mind; the name is derived from the ancient Greek word amethystos, meaning "against drunkenness".

In traditional Chinese medicine, ground amethyst was prescribed as a cure for stomach pains and bad dreams.