sedimentary

Weathered gray sandstone or siltstone

Clastic sedimentary rock, likely quartz–feldspar-rich sandstone/siltstone

AI-generated identification · may be incorrect

Gray to tan, dull to slightly granular, with weathered iron-oxide staining and possible thin bedding or fracture surfaces. Typically Mohs hardness 6–7 for quartz-rich sandstone, porous to moderately dense, with no obvious cleavage; exact texture is obscured by weathering.

Identified August 23, 2026More sedimentary →

Explore Weathered gray sandstone or siltstone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed when sand- or silt-sized sediment was deposited, compacted, and cemented, commonly by silica, calcite, or iron oxides. Its precise geological age and depositional environment cannot be determined from the photograph.

Uses & applications

Used as crushed aggregate, fill, building stone, and occasionally landscaping material; attractive fine-grained pieces may be collected but are rarely used as gemstones.

Geological facts

The pale patches may be quartz or feldspar grains, while orange-brown areas likely represent oxidation of iron-bearing minerals. A hand lens and fresh broken surface would distinguish sandstone from siltstone more reliably.

Field identification & locations

Common in sedimentary terrains worldwide. Look for visible sand grains, layered fabric, gritty texture, and reaction to dilute acid if calcite cement is suspected; likely locations include streambeds, road cuts, and eroded sedimentary outcrops.