sedimentary

Sandstone (Water-worn Pebble)

Clastic sedimentary rock (primarily SiO2)

AI-generated identification · may be incorrect

Hardness: 6-7 Mohs; Color: Tan to light brown; Luster: Dull/Earthy; Crystal Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 Mohs
Color: Tan to light brown
Luster: Dull/Earthy

Identified April 1, 2026More sedimentary →

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Physical properties

Hardness: 6-7 Mohs; Color: Tan to light brown; Luster: Dull/Earthy; Crystal Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & geological history

Formed from the accumulation and cementation of mineral particles or rock fragments (detritus). This specific specimen shows significant rounding due to fluvial (river) or coastal erosion processes.

Uses & applications

Commonly used as construction aggregate, decorative landscaping stone, and in glass making if high in quartz purity.

Geological facts

Sandstone makes up about 20-25% of all sedimentary rocks on Earth. The rounded 'egg' shape suggests it travelled miles in a high-energy water environment, like a riverbed.

Field identification & locations

Identify by its gritty texture (feels like sandpaper) and visible grains. Often found in riverbeds, beaches, and desert environments. Collectors look for unique shapes or cross-bedding patterns.