Sandstone (likely Arkosic)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, beige, or brownish-grey; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None (breaks across grains); Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of mineral particles or rock fragments. This specimen appears to be lithified sand grains deposited in a terrestrial or near-shore environment during various geologic periods.

Uses & Applications

Commonly used as a construction material (dimension stone), in glass manufacturing (if high purity silica), and as a reservoir rock for oil and natural gas.

Geological Facts

Sandstone accounts for about 20% of all sedimentary rocks on Earth. It is porous and often acts as a natural aquifer for groundwater.

Field Identification & Locations

Identify by its 'sandpaper' feel and visible grains. Found globally in deserts, riverbeds, and ocean basins. It often displays bedding planes or cross-stratification in larger outcrops.

Identified on: 4/25/2026

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