sedimentary

Weathered sandstone or quartz-rich sedimentary cobble

Indeterminate sandstone, likely arkose or quartz arenite

AI-generated identification · may be incorrect

Tan to gray, dull and earthy, with a fine-to-medium granular texture and iron-oxide staining; quartz and feldspar grains are likely. Hardness is approximately 6–7 for individual grains, with variable overall durability; no obvious cleavage or crystal faces are visible.

Identified September 15, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely lithified sand deposited in a river, shoreline, or desert environment, then cemented by silica, calcite, or iron oxides and rounded by weathering or transport. Its geological age cannot be determined from the photograph.

Uses & applications

Common sandstone is used for building stone, paving, aggregate, and landscaping; this specimen has little gem or industrial value unless it displays unusual textures or provenance.

Geological facts

The rusty yellow-brown coloration commonly comes from hydrated iron oxides such as limonite. Surface weathering can obscure the original grain size and cement.

Field identification & locations

Look for visible sand grains, gritty texture, and weak fizz or no fizz in dilute hydrochloric acid; a streak test is usually white to pale brown. Common worldwide in sedimentary basins and stream gravels.