Description
Falcon's eye is a mineral and a variety of quartz. It consists of quartz intergrown with crocidolite (blue asbestos) fibers. Falcon's eye is dark blue with a characteristic chattoyance effect when polished. Over many thousands of years, blue falcon's eye will oxidize into a golden tiger's eye. The largest locality is Griquatown in South Africa. It is also found in Wittenoom Gorge in Western Australia.
Tiger's eye is a variety of quartz. The stone's color is yellow-brown to brown, streaky, and opaque. Its locations include Africa, India, Mexico, California, and Australia. Tiger's eye is formed by the silicification of black-blue asbestos fibers called crocidolite. This process creates solid inclusions of hair-like crystals within the quartz. The oxidation of the original crocidolite fibers creates the stone's golden, lustrous limonite fibers. Tiger's eye is so named because the stone reflects light reminiscent of a tiger's eye. This slit-shaped light effect is called chatoyancy or "cat's eye." When the stone is cut cabochon (sphere), the beautiful cat's eye effect is most visible. The stone's color gives it its name: the red variety is called Cat's Eye, the blue Falcon's Eye, and the yellow Tiger's Eye (golden yellow, golden brown).
