Tigers Eye is a chatoyant gemstone, usually colored golden to red-brown and has a silky sheen. Chatoyance is inclusions of iron and quartz, which give the stone its striped appearance and an optical effect. It is a member of the Quartz family. Interestingly enough, Tiger's Eye does not begin as Quartz, but rather a mineral known as Crocidolite. Crocidolite is a blue mineral comprised of iron and sodium. The Crocidolite was gradually transformed into Quartz while maintaining its fibrous formations. Tiger's Eye is what is known in mineralogy as a pseudomorph. The term comes from the Greek for "false form." Pseudomorphs form when one mineral replaces another. The transformation begins when Quartz becomes embedded between the fibers of Crocidolite. This process can result in two different gemstones: a blue stone called hawk's eye or the golden brown stone called Tiger's Eye. When this stone is formed with Red Jasper and Hematite it becomes Tiger Iron.