Tiger Eye
Tiger eye is a chatoyant pseudomorph of quartz after crocidolite (blue asbestos) fibers, producing a wavering golden silk under light. South Africa is the dominant source.
Tiger's eye is a golden-brown, silky chatoyant variety of quartz, formed where quartz replaced fibrous crocidolite.
About Tiger Eyeextended article
Tiger's eye (tiger eye) is a chatoyant golden-brown gem variety of quartz, famous for the moving band of light — the cat's-eye effect — that sweeps across a polished surface. It formed when silica replaced fibrous blue crocidolite while preserving the fibrous structure, so the parallel fibres reflect light as a shifting sheen.
Identifying tiger's eye
Tiger's eye is hard (7, like all quartz), with golden-brown to honey colours and a strong silky lustre. The blue variety, which keeps the original crocidolite colour, is called hawk's eye, and partly oxidised reddish material is called ox eye or red tiger's eye. The chatoyant banding shows best on cabochons cut across the fibres.
Where it is found
The world's classic source is the Northern Cape Province of South Africa, where tiger's eye forms in banded ironstone; Western Australia and other regions also produce it.
For collectors and lapidaries
Strong, sharp chatoyancy, rich golden colour and good silky lustre give tiger's eye its value; hawk's eye and multicoloured pieces are also popular.
About Tiger Eye
Tiger eye forms when silica (SiO2) replaces the fibrous blue asbestos mineral crocidolite, preserving the parallel fiber structure. As the fibers oxidize, iron staining shifts the color from blue (hawk eye) through gold (classic tiger eye) and into reddish brown. The chatoyancy — that distinctive cat eye reflection — comes from light scattering off the aligned crocidolite ghost fibers within the now-silica matrix.
Identification & care
Tiger eye shares quartz physical properties: Mohs hardness 7, specific gravity around 2.65, no cleavage, conchoidal fracture, vitreous to silky luster. The diagnostic feature is the silky chatoyancy band moving across a polished surface when tilted under light. Color ranges from blue (less common, called hawk eye), through golden brown, to red (heat-treated or naturally oxidized). The fibrous internal texture is visible under magnification.
Collector context
Collector notes
The Northern Cape Province of South Africa is the dominant commercial source and provides the bulk of polished cabochons and tumbled pieces in trade. Australia and Mexico provide smaller quantities. Tiger eye is one of the most affordable chatoyant gems, with cabinet specimens of natural unpolished material harder to find than polished cabs. Collectors should be aware that some material is heat-treated to enhance the red component.
Frequently asked questions
What is Tiger Eye?
Tiger eye is a chatoyant pseudomorph of quartz after crocidolite (blue asbestos) fibers, producing a wavering golden silk under light. South Africa is the dominant source.
What is the chemical formula of Tiger Eye?
The chemical formula of Tiger Eye is SiO2.
What crystal system does Tiger Eye belong to?
Tiger Eye crystallises in the Trigonal crystal system.
References & databases
Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.