sedimentary

Iron-stained sandstone

Quartz arenite or lithic sandstone, variably cemented by iron oxides

AI-generated identification · may be incorrect

Typically Mohs hardness 6–7 for quartz grains, with rusty orange-brown color, dull to earthy luster, and visibly granular texture; porosity and uneven weathering are prominent. Exact mineralogy cannot be confirmed from a photograph, and the specimen could also be porous iron-rich conglomeratic sandstone.

Identified August 22, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when sand-sized grains accumulated, were compacted, and cemented—likely by silica, calcite, or iron oxides—then weathered at the surface. Its precise geological age and depositional environment require locality information and testing.

Uses & applications

Common sandstone is used as building stone, paving, aggregate, and occasionally as a decorative material; this irregular specimen has little commercial use.

Geological facts

The orange-red coloration generally comes from hematite or limonite coatings on pore walls and quartz grains. Strongly porous areas may indicate weathering or softer clay-rich cement.

Field identification & locations

Look for gritty quartz grains, bedding or lamination, and scratching ability near glass; dilute hydrochloric acid can reveal calcite cement by effervescence. Common worldwide in sedimentary basins, especially arid or oxidizing environments.