metamorphic

Likely weathered gneiss or granite fragment

Quartz–feldspar–mica aggregate; probably granitoid gneiss, identification uncertain from the photograph

AI-generated identification · may be incorrect

Gray, coarse-grained, irregularly fractured specimen with white/translucent quartz or feldspar and dark mica/amphibole; likely Mohs hardness 6–7, vitreous to dull luster, no obvious cleavage as a whole rock, and granular crystalline texture.

Identified September 4, 2026More metamorphic →

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At a glance

Common name: Likely weathered gneiss or granite fragment
Scientific name: Quartz–feldspar–mica aggregate; probably granitoid gneiss, identification uncertain from the photograph
Category: metamorphic
Identified: September 4, 2026
Method: Standard

AI Estimated Value

Usually $0–$5 as an unexceptional beach specimen; up to about $10–$20 if unusually attractive or locality-labeled.

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 deep in the crust from recrystallized or slowly cooled silicate-rich magma, generally Precambrian to Phanerozoic in age; the rounded surface suggests transport and beach weathering.

Uses & applications

Common equivalent rocks are used as crushed aggregate, building stone, monuments, countertops, and decorative material; this small beach specimen has mainly educational or curiosity value.

Geological facts

The pale and dark mineral contrast is typical of felsic crystalline rocks. A glassy translucent grain is likely quartz, while blockier pale grains are feldspar and reflective dark flakes may be biotite.

Field identification & locations

Look for interlocking grains, quartz that scratches glass, and feldspar cleavage; unlike sedimentary sandstone, it should not crumble into separate sand grains. Common in continental crust and glacial or coastal gravels.