sedimentary

Sandstone Cobble

Clastic Sedimentary (Sandstone)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Tan, beige, or brownish-grey; Luster: Dull/Earthy; Crystal structure: Clastic (grains); Specific gravity: 2.2–2.8

Hardness: 6-7 (Mohs scale)
Color: Tan, beige, or brownish-grey
Luster: Dull/Earthy

Identified March 18, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Tan, beige, or brownish-grey; Luster: Dull/Earthy; Crystal structure: Clastic (grains); Specific gravity: 2.2–2.8

Formation & geological history

Formed through the accumulation and cementation of mineral particles or rock fragments (clasts) usually size-matched as 'sand'. This particular specimen is a 'cobble' or 'river rock' shaped by fluvial erosion over hundreds to thousands of years.

Uses & applications

Commonly used in construction, landscaping, road base, and as decorative garden stones. Larger deposits of sandstone are used as dimension stone for buildings.

Geological facts

Sandstone preserves a record of ancient environments like deserts or riverbeds. The rounded shape (sphericity) of this specimen indicates it has traveled a long distance in a high-energy water environment like a river or shoreline.

Field identification & locations

Identify in the field by its gritty, sandpaper-like texture and rounded, smooth edges. Commonly found in riverbeds, glacial deposits, and coastal regions. It is very common worldwide.