mineral

Tumbled tiger’s-eye (likely iron-stained quartz)

Quartz, SiO₂, with fibrous crocidolite pseudomorphed by iron oxides

AI-generated identification · may be incorrect

Brown-golden color with possible chatoyant bands, vitreous to silky luster, hardness about 6.5–7 Mohs, no prominent cleavage, and specific gravity near 2.6–2.7. The rounded surface indicates tumbling or natural abrasion.

Identified September 6, 2026More mineral →

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Physical properties

Formation & geological history

Forms when blue asbestos-like crocidolite fibers are replaced by quartz and oxidized to golden-brown iron oxides, mainly during hydrothermal alteration. Major deposits are Precambrian in age, especially in South Africa and Western Australia.

Uses & applications

Used as an ornamental stone for cabochons, beads, carvings, and tumbled specimens; occasionally used in decorative objects and inexpensive jewelry.

Geological facts

Its moving reflective band, called chatoyancy, results from aligned fibrous inclusions. The pictured piece is dark and irregular, so it could also be iron-stained quartz or a lower-grade tiger’s-eye fragment.

Field identification & locations

Look for silky golden-brown bands that shift with light, glassy hardness, and resistance to scratching by steel. Common sources include South Africa, Australia, India, Brazil, and the United States.