sedimentary

Rounded iron-rich sandstone or ferruginous conglomeratic rock

Quartz-rich sandstone, locally cemented by iron oxides (hematite/goethite)

AI-generated identification · may be incorrect

Brown, fine- to medium-grained, dull to slightly earthy luster, with rounded abrasion surfaces and scattered pale quartz grains. Estimated Mohs hardness 6–7 for quartz-rich areas; cleavage absent, granular texture, and moderate-to-high density from iron cement.

Identified September 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely a sedimentary clast formed when sand was deposited, compacted, and cemented, then naturally rounded by stream or shoreline transport. Its precise geological age cannot be determined from the photograph; iron oxidation produced the brown coloration.

Uses & applications

Common sandstone is used as aggregate, building stone, paving, and occasionally as a lapidary material. This piece has modest collector value unless locality, unusual texture, or fossil content is documented.

Geological facts

The rusty coloration typically comes from iron oxides coating or cementing quartz grains rather than from metallic iron. Surface rounding indicates substantial transport or weathering.

Field identification & locations

Look for gritty texture, visible sand grains, brown-red streaking, and lack of obvious crystalline cleavage; a steel nail may scratch softer cemented areas. Common in sedimentary terrains, river gravels, beaches, and glacial deposits.