Talc

Talc [Mg₃(OH)₂(Si₄O₁₀)] is a fine-grained mineral with a soapy feel. It is a very soft mineral; you can scratch it with your fingernail. Talc comes in a variety of colors such as white, green, pink, and gray. It is a hydrated magnesium silicate that is used in a variety of products, including ceramics, paint, paper, plastics, and talcum powder. Talc is found in metamorphic rocks; this specimen is from the Allamoore mining district of West Texas and is Precambrian in age, about 1 billion years old.