sedimentary

Sandstone (River Stone)

Arenite (composed primarily of SiO2)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Brownish-green due to algae/wetness over tan/grey base; Luster: Dull to earthy; Crystal structure: Clastic (granular); Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 (Mohs scale)
Color: Brownish-green due to algae/wetness over tan/grey base
Luster: Dull to earthy

Identified June 11, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Brownish-green due to algae/wetness over tan/grey base; Luster: Dull to earthy; Crystal structure: Clastic (granular); Cleavage: None; Specific Gravity: 2.2-2.8

Formation & geological history

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments. This specimen shows significant rounding and smoothing from fluvial (river) erosion over thousands of years.

Uses & applications

Commonly used in construction (aggregate), paving, and landscaping. High-quality sandstone is used for grindstones or as architectural building stone.

Geological facts

Sandstone is one of the most common sedimentary rocks on Earth. It often contains fossils and can act as a natural aquifer for groundwater or a reservoir for oil and natural gas.

Field identification & locations

Identify by its gritty, sandpaper-like feel when dry. Usually found in stream beds, beaches, and desert environments. Look for visible layers (bedding planes) in larger outcrops.