Amethyst is a semiprecious stone and is the traditional birthstone for February.Amethyst belongs to the macrocrystalline branch of quartz. The hardness of the mineral is the same as quartz. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source) red secondary hues. Amethyst has transparent to translucent clarity and a vitreous luster.Amethyst can fade in tone if overexposed to light sources and can be artificially darkened with adequate irradiation.
Source: Wikipedia
