metamorphic

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica or iron-oxide impurities

AI-generated identification · may be incorrect

Hardness about 7 Mohs; gray, cream, and brown coloration with a granular, sugary texture and vitreous-to-dull luster. Interlocking quartz grains give it massive structure and no prominent cleavage.

Identified August 9, 2026More metamorphic →

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At a glance

Common name: Quartz-rich metamorphic rock, likely quartzite
Scientific name: Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica or iron-oxide impurities
Category: metamorphic
Identified: August 9, 2026
Method: Standard

AI Estimated Value

Approximately $5–$25 for a common hand specimen; $30–$100+ if unusually attractive, polished, 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

Hardness about 7 Mohs; gray, cream, and brown coloration with a granular, sugary texture and vitreous-to-dull luster. Interlocking quartz grains give it massive structure and no prominent cleavage.

Formation & geological history

Formed when quartz-rich sandstone was recrystallized under substantial heat and pressure during mountain-building; individual specimens may range from Precambrian to Phanerozoic age.

Uses & applications

Used as crushed stone, aggregate, landscaping rock, countertops, building stone, and occasionally as a decorative or lapidary material.

Geological facts

Quartzite is usually harder and more resistant to weathering than its sandstone precursor; iron oxides commonly produce the brown or rusty patches visible here.

Field identification & locations

Identify it by testing whether it scratches glass, observing fused-looking quartz grains, and checking that broken surfaces pass through grains rather than around sand grains. Common in metamorphic mountain belts worldwide, including the Appalachians, Rocky Mountains, India, Brazil, and Scandinavia.