sedimentary
River Pebble (Granitic Sandstone)
Clastic sedimentary rock (Lithic Arenite)
Hardness: 6-7 (Mohs); Color: Tan, beige with salt-and-pepper specks; Luster: Dull/Earthy; Structure: Granular/Clastic; Specific Gravity: Approx 2.6
- Hardness
- 6-7 (Mohs)
- Color
- Tan, beige with salt-and-pepper specks
- Luster
- Dull/Earthy
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Physical properties
Hardness: 6-7 (Mohs); Color: Tan, beige with salt-and-pepper specks; Luster: Dull/Earthy; Structure: Granular/Clastic; Specific Gravity: Approx 2.6
Formation & geological history
Formed through the weathering of parent granitic rocks, followed by the transport and deposition of sand-sized grains in a river or coastal environment, subsequently lithified and then eroded/polished by water action.
Uses & applications
Used primarily in landscaping, decorative river rock arrangements, and construction aggregate.
Geological facts
The rounded shape indicates a long history of water transport, where constant collisions with other rocks smoothed out the sharp edges of the original fragment.
Field identification & locations
Commonly found in riverbeds, glacial outwashes, and beaches. Identify by its rounded, oblong shape and visibility of individual grains of quartz and feldspar.
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