sedimentary

Quartz-rich sandstone (possibly arkosic sandstone)

Clastic sandstone, mainly quartz (SiO₂) with feldspar and iron-oxide cement

AI-generated identification · may be incorrect

Usually Mohs 6–7 for quartz grains, though the rock is weaker; tan-gray, gritty, and dull to slightly sparkly, with visible sand-sized grains and no obvious cleavage. Individual grains are commonly rounded to subangular and cemented into a porous mass.

Identified August 27, 2026More sedimentary →

Explore Quartz-rich sandstone (possibly arkosic sandstone) 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 accumulated, was compacted, and cemented by silica, calcite, or iron oxides; the specimen appears weathered and naturally rounded. Its exact geological age cannot be determined from the photograph.

Uses & applications

Used as building stone, paving, aggregate, and a source of silica; attractive fine-grained pieces may be collected but generally have little commercial value.

Geological facts

Sandstone’s texture records ancient transport by rivers, beaches, dunes, or glaciers. A hand lens and a drop of dilute hydrochloric acid can help identify cement: calcite cement may fizz, while quartz-rich grains do not.

Field identification & locations

Common worldwide, especially in sedimentary basins; likely locations include riverbeds, coastal exposures, deserts, and road cuts. Scratch individual grains with steel only weakly, and inspect for bedding, sorting, and visible quartz/feldspar.