sedimentary

Weathered quartz-rich river stone

Chert or silicified limestone/quartzite; exact identification requires testing

AI-generated identification · may be incorrect

Tan-brown, fine-grained, dull to slightly waxy luster, rounded and waterworn with patchy iron-oxide staining. Likely hardness about 6–7 if chert/quartzite; cleavage absent and specific gravity roughly 2.6.

Identified August 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably formed as a silica-rich sedimentary or altered carbonate rock, then rounded by river or beach transport and chemically weathered. Its geological age cannot be determined from the photograph.

Uses & applications

Primarily a decorative or educational specimen; comparable material may be used as aggregate, roadstone, or occasionally lapidary rough if it cuts attractively.

Geological facts

The pale, massive appearance and lack of visible crystals are consistent with microcrystalline quartz, but the surface could also represent weathered limestone or quartzite.

Field identification & locations

Test with a steel file or glass: quartz-rich material should resist scratching glass, while limestone will fizz with dilute hydrochloric acid or vinegar. Common in gravel bars, beaches, and weathered outcrops; the image alone cannot establish locality.