Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)
Rock Type: mineral

Physical Properties
Hardness: 6.5-7 (Mohs scale), Color: Golden brown to yellowish brown, Luster: Silky/Vitreous, Structure: Trigonal/Fibrous, Cleavage: None, Specific Gravity: 2.64-2.71.
Formation & Geological History
Formed when quartz replaces fibrous crocidolite (blue asbestos) through a process of pseudomorphism, where the original shape of the fibers is preserved but the mineral composition is changed to silica. It is often found associated with iron formations.
Uses & Applications
Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular collectible gemstone due to its chatoyancy. Also used in spiritual or metaphysical practices.
Geological Facts
Tiger's eye belongs to the chalcedony family. It exhibits a unique optical effect known as chatoyancy (cat's eye effect), where reflected light moves across the fibrous bands of the stone as it is turned.
Field Identification & Locations
Identify by its distinct golden-brown banding and silky luster. It is most commonly found in South Africa, Western Australia, India, and Burma. Collectors should look for high-contrast bands and a smooth, chatoyant polish.
Identified on: 4/16/2026
Mode: Standard