Sandstone (Pebble)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, brown, and reddish-orange due to iron oxide staining; Luster: Dull/Earthy; Crystal structure: Clastic (grainy texture); Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. This specific specimen has been significantly rounded by fluvial or marine erosion, indicating a history in a riverbed or shoreline.

Uses & Applications

Used in construction, landscaping as decorative pebbles, and as a reservoir rock for oil and natural gas in geological basins.

Geological Facts

Sandstone accounts for roughly 20 to 25 percent of all sedimentary rocks in the Earth's crust. Its high porosity makes it a valuable aquifer for groundwater.

Field Identification & Locations

Identify by its 'sandpaper' feel and visible grains under magnification. Commonly found in riverbeds, beaches, and desert environments. For collectors, look for unique weathering patterns or banding.

Identified on: 4/25/2026

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