metamorphic
Polished red tiger’s-eye (likely)
Quartz pseudomorph after crocidolite; chiefly SiO₂ with iron oxides
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; reddish-brown to dark brown with silky chatoyancy and vitreous-to-silky luster. Microcrystalline quartz, with no obvious cleavage; specific gravity about 2.6–2.7.
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Physical properties
Hardness about 6.5–7 Mohs; reddish-brown to dark brown with silky chatoyancy and vitreous-to-silky luster. Microcrystalline quartz, with no obvious cleavage; specific gravity about 2.6–2.7.
Formation & geological history
Formed when crocidolite fibers were replaced by quartz during low-grade metamorphic alteration, with iron oxidation producing the red color. Most commercial material comes from Precambrian rocks of South Africa and western Australia.
Uses & applications
Used for cabochons, beads, carvings, ornaments, and small polished collectibles; it is generally inexpensive but attractive.
Geological facts
The moving cat’s-eye sheen is caused by aligned fibrous inclusions, visible when the stone is rotated under directional light. Red material is often heat-treated or naturally iron-rich.
Field identification & locations
Identify it by its parallel silky banding, chatoyancy, brown-red color, and quartz-like hardness; streak is usually white to colorless. Common sources include South Africa, Australia, India, and Namibia.
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