Amethyst: February Birthstone
Amethyst is a well known mineral and gemstone. It is the purple variety of the mineral Quartz, and its most valuable and prized variety.
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.
When used as a gemstone, Amethyst is often heat treated to deepen the color, or to transform it into Citrine. Some varieties may also change to a light green color, which is given the trade name "Prasiolite", or "Green Amethyst."
Bismuth: Also an Element!
Bismuth is an uncommon mineral composed of the element of the same name. It usually forms in ugly masses, though occasionally does form in aesthetic lustrous crystals. Bismuth has a metallic-white color with a slight reddish or pinkish hue. This pure color will only be present on an untarnished (i.e. freshly broken) surface, since Bismuth tarnishes yellow to dark-gray.