sedimentary

River Sandstone (Lithic Arenite)

Lithic Sandstone (SiO2 dominated with lithic fragments)

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale; Color: Brown, tan, or grey due to iron oxide staining; Luster: Dull to earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8.

Hardness: 6-7 on Mohs scale
Color: Brown, tan, or grey due to iron oxide staining
Luster: Dull to earthy

Identified June 24, 2026More sedimentary →

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Physical properties

Hardness: 6-7 on Mohs scale; Color: Brown, tan, or grey due to iron oxide staining; Luster: Dull to earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8.

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral grains and rock fragments. This specimen appears water-worn, indicating it was transported and smoothed by a river or stream over thousands of years.

Uses & applications

Primarily used as a construction aggregate, for road base, or in glass manufacturing if high in quartz. Smooth river stones are popular in landscaping and decorative aquariums.

Geological facts

Sandstone makes up about 10-20% of the Earth's sedimentary rocks. Its porosity makes it a critical reservoir for groundwater and petroleum.

Field identification & locations

Identify by its gritty texture (feels like sandpaper) and visible grains. Commonly found in riverbeds, canyons, and coastal areas. This specific piece is a 'chert-rich' or 'lithic' sandstone found in alluvial deposits.