Amatrice Hill Variscite Deposit, Tooele County, Utah

Abstract

Variscite (A1PO4 ·2H2 O) is found in Utah in three principal deposits: Clay Canyon, Lucin, and Amatrice Hill. Amatrice Hill, on the east flank of the Stansbury Mountains near Stockton, is the most recently found deposit and the only one mined at present. The mineral occurs as nodules in faulted and brecciated limestones of the Pennsylvanian-Permian Oquirrh Formation. Variscite resembles turquoise in color and is used similarly in jewelry. It is softer, however, and generally not as durable. Larger pieces are used for decorative stone. Three principal types based on pattern and color are recognized: jade, apple blossom, and cobweb. A blue color variant has been called variquoise.