China
Originally identified in 1992 in Namibia by mineralogist Sid Peters, the present example of pietersite is from a newer, limited find in China. A variety of riebeckite, it crystallizes in the form of masses and its structure is a result of inclusions in jasper where the inclusions are pseudomorphs after a crocidolite-type asbestos. The process begins with hawk's eye—the name given to the blue variety of tiger's eye—an opaque aggregate which is formed when quartz replaces the blue/green mineral crocidolite creating iridescent planes or fractures with a silky luster. Tiger's eye is created when the iron from the decomposed crocidolite oxidizes changing it to a golden brown color. Pietersite is then formed by a process known as brecciation which occurs when the fibrous structure of both tiger's eye and hawk's eye are broken by the earth's tectonic forces. The tiny fragments are later naturally cemented together by quartz creating a finished product with multiple hues and superb chatoyancy. Pietersite is excellent for use in jewelry and for ornamental carving due to its very high hardness of 7, its toughness and lack of cleavage. Diameter 5in