(Mg,Al)₆(Si,Al)₄O₁₀(OH)₈

This sample of clinochlore is displayed in the Smithsonian Museum of Natural History. Clinochlore is a mineral that contains four of the big 8 elements of the Earth's crust. The composition is (Mg,Al)₆(Si,Al)₄O₁₀(OH)₈. The sample at left is about 10 cm across and is from Kop chrome mine, Daglari, Anatolia, Turkey. This sample is described as chromian clinochlore, presumably because inclusions of chromium in the chromium mining area contribute the purple color. Other samples of clinochlore have colors from green to blue.