sedimentary

Quartz-rich sandstone or chert fragment

Indeterminate siliciclastic rock; likely quartz arenite or weathered chert

AI-generated identification · may be incorrect

Tan-brown, fine to medium-grained, dull to slightly sugary luster, with pale angular grains or patches. Likely hardness about 6–7 if quartz-rich; cleavage absent, fracture irregular to subconchoidal, and specific gravity roughly 2.4–2.7.

Identified September 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably formed from compacted and cemented quartz sand, or from silica-rich chemical sediment; its exact age and formation environment cannot be determined from the photograph. Brown coloration may reflect iron-oxide staining and weathering.

Uses & applications

Common sandstone is used for building stone, paving, aggregate, and landscaping; chert is used as aggregate and historically for stone tools. This small fragment has negligible commercial value.

Geological facts

The image does not show diagnostic crystals, fossils, bedding, or a fresh fracture, so a precise identification is not possible visually. A glass-scratch test can help: quartz-rich material should scratch ordinary glass.

Field identification & locations

Look for visible sand grains and layering for sandstone; a very smooth waxy surface and sharp conchoidal fracture suggest chert. Common sources include sedimentary basins worldwide.