sedimentary

Sandstone (with Concretion)

Arenite / Quartzose Sandstone

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale for quartz grains); Color: Tan, brown, buff; Luster: Dull or earthy; Structure: Clastic, granular; Cleavage: None; Specific Gravity: 2.3-2.4

Hardness: 6-7 (Mohs scale for quartz grains)
Color: Tan, brown, buff
Luster: Dull or earthy

Identified April 26, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale for quartz grains); Color: Tan, brown, buff; Luster: Dull or earthy; Structure: Clastic, granular; Cleavage: None; Specific Gravity: 2.3-2.4

Formation & geological history

Formed through the accumulation and cementation of mineral particles or rock fragments (silt and sand). The rounded feature is a concretion formed by the precipitation of mineral cement in the spaces between particles.

Uses & applications

Used primarily as a construction material (dimension stone), in glass manufacturing (if high silica), and as a reservoir rock for oil, gas, and water.

Geological facts

Sandstone makes up about 20-25% of all sedimentary rocks on Earth. Concretions found within them are often mistaken for fossils or meteorites due to their unusual shapes.

Field identification & locations

Identify in the field by its gritty texture (feels like sandpaper) and visible sand grains. Concretions will appear as harder, distinct masses within the softer surrounding layers.