sedimentary

Likely weathered jasper or iron-rich chert

Microcrystalline quartz (SiO₂), with iron-oxide staining

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; reddish-brown with pale cream mottling, dull to slightly waxy luster, and no obvious cleavage. The irregular shape and granular-looking surface suggest a naturally weathered siliceous stone, though the image alone cannot confirm its identity.

Identified September 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed from silica-rich sediment or altered volcanic material later cemented and stained by iron oxides; its precise geological age and locality are indeterminate. Weathering rounded the exposed fragment.

Uses & applications

Common jasper and chert are used as lapidary material, cabochons, beads, carvings, and decorative stone; ordinary pieces have little industrial or construction value.

Geological facts

Jasper is an opaque variety of chalcedony or microcrystalline quartz, while chert is a broader sedimentary silica term; the boundary between them can be indistinct.

Field identification & locations

Look for strong resistance to scratching by steel, a glassy fracture, and absence of fizz with dilute acid; quartz-rich material should not be easily scratched by a knife. Common examples occur in gravel beds, river deposits, and iron-rich sedimentary formations.