sedimentary or metamorphic

Weathered quartz-rich rock, likely chert or quartzite

Microcrystalline quartz (SiO₂), possibly with iron-oxide staining

AI-generated identification · may be incorrect

Tan to cream, dull-to-waxy luster, fine-grained and massive; quartz hardness is about Mohs 7, with no obvious cleavage. The rounded surface and granular texture suggest weathering and abrasion.

Identified August 21, 2026More sedimentary or metamorphic →

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Physical properties

Tan to cream, dull-to-waxy luster, fine-grained and massive; quartz hardness is about Mohs 7, with no obvious cleavage. The rounded surface and granular texture suggest weathering and abrasion.

Formation & geological history

Likely formed from silica-rich sediment that lithified into chert, or from sandstone metamorphosed into quartzite; the specimen’s precise age and origin cannot be determined from the image alone.

Uses & applications

Common chert is used historically for sharp tools and occasionally aggregate; quartzite is used as building stone, paving, and aggregate. This piece has little commercial value unless locality or unusual features are established.

Geological facts

The pale color and rusty patches may reflect iron oxides, while the irregular fracture appears consistent with quartz-rich material. A steel file should not scratch it if it is quartz-rich.

Field identification & locations

Look for a glassy or waxy fracture, absence of visible large crystals, and resistance to scratching by steel. Common sources include river gravels, sedimentary formations, and metamorphic terrains worldwide.