Variscite is a hydrated aluminum phosphate is formed when phosphate-rich water reacts with aluminum-rich rocks near the surface. In its purest form, it's white, but metals like chromium and vanadium give it its green color. Variscite can be discolored by cosmetics, oils, and acids. It should be cleaned with a damp cloth and avoided from getting wet. Variscite is usually green, but can also be yellow, orange, or black. It's often mottled or veined, with white veins of crandallite, a calcium aluminum phosphate mineral.