Dims: 3.6 x 3.3 x 3.0" (9.1 x 8.4 x 7.6 cm)
Wt: 2 lbs., 4.0 oz. (1.022 kg)
Boron, California, U.S.A.
This large hand specimen consists of one of the largest Colemanite crystals that I have yet seen. It has visible dimensions of 4.5 x 3.5 x 2.9" (11.4 x 8.9 x 7.4 cm) and is incomplete due to its intergrowth with other, broken Colemanite crystals and what may have been a base of trona which is not present on the piece. The crystal shows several areas of human-induced damage, but most of it is not severe. Its chubby, monoclinic prismatic form is reasonably good given its intergrowth, and it has well-defined edges and clean faces that possess a rather dull pearly luster. Its color ranges from colorless to a milky-white, showing respective transparence to translucence. There is only a small amount of what I think is trona that may have been a host rock.