metamorphic

Weathered quartzite or quartz-rich metamorphic rock

Quartzite, predominantly microcrystalline SiO₂, possibly with mica, feldspar, and iron-oxide staining

AI-generated identification · may be incorrect

Hardness about 7 Mohs; pale gray, cream, tan, and bluish-gray; generally dull to vitreous luster with interlocking granular texture and no obvious cleavage. Dense and resistant, though this specimen is heavily weathered and fractured.

Identified August 29, 2026More metamorphic →

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At a glance

Common name: Weathered quartzite or quartz-rich metamorphic rock
Scientific name: Quartzite, predominantly microcrystalline SiO₂, possibly with mica, feldspar, and iron-oxide staining
Category: metamorphic
Identified: August 29, 2026
Method: Standard

AI Estimated Value

$1-$10 as an ordinary loose specimen; up to roughly $20-$50 if unusually attractive, labeled, or locality-specific.

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 sandstone recrystallized under heat and pressure during regional metamorphism, commonly hundreds of millions to billions of years ago. Surface oxidation and weathering produced the tan-brown staining.

Uses & applications

Used as crushed stone, road aggregate, building stone, paving, countertops, and decorative material; this rough piece has little jewelry value.

Geological facts

Quartzite commonly breaks across grains rather than around them, unlike sandstone, and can scratch ordinary glass. The blue-gray areas may reflect mica or other metamorphic minerals.

Field identification & locations

Likely quartzite if a fresh edge is sugary and crystalline and the rock scratches glass; sandstone would show looser grains and crumble more readily. Common in metamorphic mountain belts worldwide, including the Appalachians, Rocky Mountains, Scandinavia, and India.