metamorphic
Polished tiger’s-eye
Chatoyant quartz (microcrystalline quartz, SiO₂, with fibrous riebeckite/crocidolite pseudomorphs)
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; brown, golden, and black banding with silky chatoyancy and a vitreous-to-waxy luster. Massive, non-cleaving, fine-grained structure; the pictured piece appears polished or naturally water-worn.
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Physical properties
Hardness about 6.5–7 Mohs; brown, golden, and black banding with silky chatoyancy and a vitreous-to-waxy luster. Massive, non-cleaving, fine-grained structure; the pictured piece appears polished or naturally water-worn.
Formation & geological history
Forms when quartz replaces fibrous crocidolite during low-grade metamorphism, preserving aligned fibers that create the cat’s-eye effect. Major deposits formed in Precambrian rocks, especially in South Africa and Western Australia.
Uses & applications
Used for beads, cabochons, carvings, ornaments, and tumbled stones; attractive material is popular in inexpensive jewelry and mineral collections.
Geological facts
Its moving reflective band is caused by aligned internal fibers, not a true crystal cleavage. Golden tiger’s-eye may grade into red mahogany or blue hawk’s-eye varieties.
Field identification & locations
Identify it by its chatoyant stripe, hardness, opaque brown-gold color, and parallel bands; common sources include South Africa, Australia, India, Namibia, and the United States. A polished surface and rounded elongated shape indicate lapidary or water-worn treatment.
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