metamorphic

Polished or weathered quartz-rich rock, possibly quartzite

Quartzite; predominantly quartz (SiO₂), with possible iron-oxide staining and minor mica or feldspar

AI-generated identification · may be incorrect

Appears to be a rounded, cut or naturally fractured specimen with a white granular rim and dark gray-blue, sparkly interior. Quartz has Mohs hardness 7, vitreous luster, no cleavage, and a specific gravity near 2.65; exact identification is limited by the photograph.

Identified September 5, 2026More metamorphic →

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At a glance

Common name: Polished or weathered quartz-rich rock, possibly quartzite
Scientific name: Quartzite; predominantly quartz (SiO₂), with possible iron-oxide staining and minor mica or feldspar
Category: metamorphic
Identified: September 5, 2026
Method: Standard

AI Estimated Value

Common field specimen: $1–$10; polished or unusually attractive specimens: approximately $10–$40.

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

Quartzite forms when quartz-rich sandstone is recrystallized during regional metamorphism, typically during mountain-building events; its age depends on the source sandstone and metamorphic belt. The dark center may reflect mica, graphite, iron oxides, or a different enclosed rock.

Uses & applications

Quartzite is used as crushed stone, aggregate, building stone, and decorative material; attractive pieces may be polished for collections or crafts.

Geological facts

Its granular quartz texture and resistance to scratching distinguish it from sandstone. A steel file should not scratch quartz-rich areas, while glass can usually be scratched by them.

Field identification & locations

Common in metamorphic mountain belts worldwide, including the Appalachian, Rocky, and European mountain regions. Confirm with a fresh surface, hardness test, and close inspection for interlocking quartz grains; the dark material could require laboratory testing.