metamorphic

Weathered quartz-bearing metamorphic rock

Likely quartz–feldspar schist or gneiss, possibly with iron-oxide alteration

AI-generated identification · may be incorrect

Gray to tan, coarse-grained, sparkly granular texture with probable quartz and feldspar plus dark mica; locally foliated and fractured. Hardness approximately 6–7, vitreous to pearly luster, low apparent cleavage overall, and specific gravity around 2.6–2.8.

Identified September 7, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely formed when quartz- and feldspar-rich sedimentary or igneous rock was buried, heated, and deformed during regional metamorphism; the rusty brown areas reflect later oxidation. Exact geological age and locality cannot be determined from the photograph.

Uses & applications

Unlikely to have commercial value as an individual specimen; similar rocks are used as crushed aggregate, dimension stone, and occasionally decorative building stone.

Geological facts

The glittering grains are probably mica or reflective quartz/feldspar surfaces, while dark linear zones may represent biotite-rich foliation or fractures. A fresh broken surface and a hardness test would improve identification.

Field identification & locations

Look for aligned platy mica, alternating light and dark bands, abundant quartz, and feldspar grains; common in metamorphic terrains worldwide, including mountain belts. Estimated value: $1–$15 for an ordinary hand specimen, potentially $20–$50 if attractively banded and locality-documented.