metamorphic

Quartzite (probable)

Quartzite; recrystallized quartz, SiO₂, with minor iron-oxide and possibly feldspar/mica impurities

AI-generated identification · may be incorrect

Typically very hard (Mohs 7), pale gray to white with rusty brown weathering, vitreous to sugary luster, and interlocking granular crystals; lacks obvious cleavage and commonly fractures irregularly. The specimen appears massive and strongly foliated or layered, so quartz-rich metamorphic sandstone or quartz-mylonite i…

Identified September 7, 2026More metamorphic →

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At a glance

Common name: Quartzite (probable)
Scientific name: Quartzite; recrystallized quartz, SiO₂, with minor iron-oxide and possibly feldspar/mica impurities
Category: metamorphic
Identified: September 7, 2026
Method: Standard

AI Estimated Value

Approximately $10-$75 as an undocumented rough landscaping or collector specimen; $100-$300+ if unusually large, attractive, or locality-documented.

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 was metamorphosed under elevated pressure and temperature, welding quartz grains together; the brown surface reflects oxidation of iron-bearing minerals. Precise age cannot be determined from the photograph and depends on its source terrane.

Uses & applications

Used as crushed stone, road aggregate, riprap, building stone, and decorative landscape rock; attractive varieties are used for slabs and sculpture. This large rough specimen has modest commercial value unless locality or unusual structure is documented.

Geological facts

Quartzite commonly resists weathering more strongly than surrounding rocks and forms ridges, cliffs, and durable boulders. A steel nail or knife should not scratch fresh quartzite, although surface weathering may be softer.

Field identification & locations

Common in metamorphic belts worldwide, including the Appalachian, Rocky, and Precambrian shield regions. Confirm by testing a fresh surface: quartz grains should be fused, with no sandy grain pullout; acid produces no fizz.