Amethyst

Amethyst is crystalline quartz in colors ranging from pale lilac to deep reddish purple. With a relatively high hardness of 7, the February birthstone is a fine face-table jewelry gem for all purposes. Natural amethyst receives its color from the presence of iron and other trace elements as well as natural irradiation. Its name derives from the Greek 'Amethystos', which means 'not drunken', as Amethyst in antiquity was thought to ward off drunkenness. The color of some Amethyst specimens from certain localities slowly fade upon prolonged exposure to light. 

Color: Pale lilac to deep reddish purple.

Hardness: 7 on Mohs scale.