sedimentary

Riverstone (Sandstone Pebble)

Arenite (SiO2 with various lithic fragments)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Tan, brown, or buff color; Luster: Dull to earthy; Crystal structure: Clastic (made of sand-sized grains); Cleavage: None; Specific gravity: 2.2-2.8

Hardness: 6-7 (Mohs scale)
Color: Tan, brown, or buff color
Luster: Dull to earthy

Identified June 26, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Tan, brown, or buff color; Luster: Dull to earthy; Crystal structure: Clastic (made of sand-sized grains); Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed from the accumulation and cementation of mineral particles or rock fragments. This specific specimen has been chemically and physically weathered and rounded by the action of water in a river or stream environment over hundreds to thousands of years.

Uses & applications

Used primarily in landscaping, construction aggregate, and as decorative garden stones. Larger deposits are quarried for building stone.

Geological facts

Riverstones are among the most common geological specimens found globally. They serve as historical records of water flow and erosion, often being transported miles from their original source.

Field identification & locations

Identify by the presence of visible sand grains and its smooth, rounded exterior caused by river transport. Commonly found in riverbeds, deltas, and glacial outwash plains. Look for a gritty texture compared to smoother basalt or limestone.