sedimentary
Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily Quartzite/Arenite)
Hardness: 6-7 Mohs; Color: Tan, brown, or buff with visible bedding planes; Luster: Dull/Earthy; Structure: Fine-grained clastic; Cleavage: None; Specific Gravity: 2.2-2.8
- Hardness
- 6-7 Mohs
- Color
- Tan, brown, or buff with visible bedding planes
- Luster
- Dull/Earthy
Identified More sedimentary →
Explore Sandstone (River Pebble) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Tan, brown, or buff with visible bedding planes; Luster: Dull/Earthy; Structure: Fine-grained clastic; Cleavage: None; Specific Gravity: 2.2-2.8
Formation & geological history
Formed from the accumulation and cementation of sand-sized mineral particles or rock fragments. The rounded shape indicates significant water erosion, likely from a riverbed or stream environment, occurring over thousands to millions of years.
Uses & applications
Common river pebbles are used for decorative landscaping, aquarium substrate, and as aggregate in construction and concrete. Larger sandstone deposits provide building stone.
Geological facts
Sandstone contains a record of the past, often preserving ripple marks, cross-bedding, and occasionally fossils that indicate the flow direction of prehistoric rivers or winds of ancient deserts.
Field identification & locations
Identify by its gritty texture (feels like sandpaper) and visible layering (stratification). Found globally in riverbeds, beaches, and sedimentary basins. Collectors often look for unique erosion patterns or 'lucky' smooth shapes.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary