Hemimorphite, a hydrous zinc silicate, a mineral that may occur as light green to blue crusts on various rocks or more rarely in slender crystal groups, usually white or clear crystalline. Its crystal symmetry is orthorhombic. This mineral was formerly known as calamine and is mined in association with ores of lead and zinc. The microcrystalline hemimorphite covering the host rock in this sample has a botryoidal (grapelike) appearance. Sample from Magistral del Oro, Durengo, Mexico. Actual width of specimen is 120 mm.