mineral

Polished tiger’s-eye

Quartz variety, macrocrystalline SiO₂ with chatoyant amphibole/fibrous inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; golden-brown to dark brown bands, silky vitreous luster, opaque, and typically lacking visible cleavage. The polished surface shows chatoyancy—a reflective, cat’s-eye-like band caused by aligned fibers.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Forms when crocidolite asbestos fibers are pseudomorphed and silicified by quartz, commonly during hydrothermal alteration of iron-rich rocks. Most commercial material is Precambrian and comes from South Africa, Western Australia, India, and Namibia.

Uses & applications

Used for cabochons, beads, tumbled stones, carvings, and decorative objects; it is generally an inexpensive collector gemstone rather than a structural material.

Geological facts

The specimen appears to be a polished or tumbled piece, possibly with adjacent darker blue-gray material suggesting an iron-rich tiger’s-eye variety or mixed banding. Its chatoyant sheen is strongest when viewed across the fiber direction under a moving light.

Field identification & locations

Identify it by its parallel golden bands, silky moving reflection, opaque brown body, and quartz-like hardness; it should resist scratching by steel but not by hardened quartz. Common rough material occurs in altered banded iron formations.