metamorphic

Weathered gneiss or granite fragment

Feldspar–quartz–mica rock; likely granitoid-derived gneiss

AI-generated identification · may be incorrect

Tan, granular, and irregular with a dull to weakly vitreous luster; visible grains suggest quartz and feldspar with minor mica. Approximate hardness 6–7 Mohs; no obvious cleavage or crystal faces are visible.

Identified September 19, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely a natural fragment weathered from granitic or gneissic bedrock, though the image alone cannot establish its exact identity or age. Such rocks commonly formed deep in the crust during Precambrian to Phanerozoic geological events.

Uses & applications

Common granite/gneiss is used as crushed aggregate, road material, building stone, and landscape rock; this small fragment has negligible commercial value.

Geological facts

The specimen appears embedded in or lying on a paved surface beside soil, and its brown color may reflect iron-oxide weathering or surface staining rather than its original composition.

Field identification & locations

Look for interlocking quartz, feldspar, and mica grains; gneiss usually shows compositional banding, while granite is more uniformly granular. Common worldwide; an isolated fragment is typically worth $0–$5.