metamorphic

Polished tiger’s-eye (likely iron-rich quartzite)

Quartzite composed mainly of SiO₂, with fibrous crocidolite pseudomorphs oxidized to iron oxides

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; golden-brown to reddish-brown, with silky chatoyancy and vitreous-to-silky luster. The layered appearance reflects fibrous quartz and iron-oxide bands; cleavage is absent and fracture is uneven to conchoidal.

Identified September 6, 2026More metamorphic →

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At a glance

Common name: Polished tiger’s-eye (likely iron-rich quartzite)
Scientific name: Quartzite composed mainly of SiO₂, with fibrous crocidolite pseudomorphs oxidized to iron oxides
Category: metamorphic
Identified: September 6, 2026
Method: Standard

AI Estimated Value

About $10–$50 for common polished specimens; $75–$300+ for large, strongly chatoyant, well-finished pieces.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed when quartz-rich rock underwent metamorphism, preserving and replacing asbestos-like fibers with quartz and limonite/hematite. Most gem-quality material formed in Precambrian rocks, especially in South Africa and Western Australia.

Uses & applications

Cut and polished for cabochons, carvings, spheres, bookends, and ornamental objects; valued as a decorative gemstone rather than for industrial construction.

Geological facts

The moving cat’s-eye sheen is caused by aligned fibers reflecting light. Reddish zones indicate stronger oxidation of iron minerals, producing a variety sometimes called red tiger’s-eye.

Field identification & locations

Identify by its hardness, dense quartz-like feel, parallel silky bands, and chatoyant flash that moves when tilted; it should not fizz in dilute acid. Common sources include South Africa, Australia, India, Namibia, and the United States.