Rock Identifier
Tumbled sandstone pebble (Sandstone, primarily quartz (SiO₂) with feldspar and iron-oxide cement) — sedimentary
sedimentary

Tumbled sandstone pebble

Sandstone, primarily quartz (SiO₂) with feldspar and iron-oxide cement

AI-generated identification · may be incorrect

Typically Mohs 6–7 for quartz grains, but variable overall; tan-brown, matte to slightly earthy luster, visibly granular texture, and weak or no cleavage. The rounded shape and parallel darker bands suggest natural abrasion of layered sandstone.

Identified More sedimentary
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Physical properties

Typically Mohs 6–7 for quartz grains, but variable overall; tan-brown, matte to slightly earthy luster, visibly granular texture, and weak or no cleavage. The rounded shape and parallel darker bands suggest natural abrasion of layered sandstone.

Formation & geological history

Formed when sand accumulated, compacted, and cemented—likely during a sedimentary basin’s burial history; its precise geological age cannot be determined from the image. Later transported and rounded by water or glacial movement, or artificially tumbled.

Uses & applications

Used as building and paving stone, aggregate, landscaping material, and decorative specimens; this small piece has mainly educational or modest collecting value.

Geological facts

Iron oxides commonly produce the brown coloration, while bedding or cross-bedding creates the visible bands. Sandstone can preserve ripple marks, fossils, and ancient environmental clues.

Field identification & locations

Look for individual sand grains, layered bedding, and a gritty feel; it should not fizz with dilute acid unless carbonate cement is present. Common worldwide, especially in river gravels and sedimentary-rock regions.