Chocolate dogtooth calcite, largeLocale: Santa Eulalia, Chihuahua, Mexico Approx size: 4 x 3 x 2. 5" Approx weight: 652g (about 1 1 3 lb) Known by the trade name "chocolate dogtooth calcite," this type of calcite from the famed Santa Eulalia mining district grows in hedgehog clusters of sharp dogtooth (scalenohedral) crystals. The variety gets its distinctive opaque brown appearance from iron oxides; a layer of hematite included calcite is deposited on the surface during a later