Serpentine (mineral)

An ornamental mineral composed of hydrated magnesium silicate, having a greasy or silky luster, a slightly soapy feel, and a tough, conchoidal fracture. It ranges in color from yellow, green, gray, brown, or black, with crystals of green olivine and black veins or patches. Serpentine has been gathered or mined since Paleolithic times, used for decorative vessels, jewelry, building stones, and as a source of abestos.