Tiger eye raw slabs from South Africa.

Tiger's eye is a variety of quartz. The color of the stone is tan to brown, streaky and opaque. Sites include Africa, India, Mexico, California and Australia. Tiger's eye is caused by the silicification of black-blue asbestos fibers called crocidolite. This creates solid inclusions of hair-like crystals in the quartz. The oxidation of the original crocidolite fibers creates the gold shiny limonite fibers of the stone. Tiger's eye is so called because the stone has a light reflection that is reminiscent of a tiger's eye. This slit-shaped light effect is called chatoyeren or 'cat's eye effect'. When the stone is cabochon (convex) cut, the beautiful cat's eye effect is best visible. The color of the stone gives it its name: the red type is called Cat's Eye, the blue Falcon's Eye and the yellow Tiger's Eye (golden yellow, golden brown).