is a variety of crystalline quartz in colors ranging from pale lilac to deep reddish purple and ranging from transparent to translucent is known as amethyst. Green amethyst is known as prasiolite, and is produced by heat treatment. Value per carat in violet purple amethyst, unlike many gems, doesn't rise exponentially with weight as it is readily available in large sizes; but depends almost entirely on color. "Siberian" deep purple amethyst with red and blue flashes commands the highest prices.
Amethyst Gemstone meaning
Crystalline quartz in shades of purple, lilac or mauve is called amethyst, a stone traditionally worn to guard against drunkedness and to instill a sober mind. The word amethyst comes from the Greek meaning "without drunkenness" and amethyst is believed to protect one from poison
Amethyst is a meditative and calming stone which works in the emotional, spiritual, and physical planes to promote calm, balance, and peace. It is also used to eliminate impatience.