sedimentary

Sandstone

Arenite (SiO2 based)

Hardness: 6-7 Mohs; Color: Tan, yellow, or brown with darker speckled spots; Luster: Dull/Earthy; Crystal structure: Clastic/Granular; Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 Mohs
Color: Tan, yellow, or brown with darker speckled spots
Luster: Dull/Earthy

Identified June 1, 2026More sedimentary →

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Physical properties

Hardness: 6-7 Mohs; Color: Tan, yellow, or brown with darker speckled spots; Luster: Dull/Earthy; Crystal structure: Clastic/Granular; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of mineral particles or rock fragments (sand) over millions of years, typically in river beds, deserts, or marine environments. This specimen appears water-worn and smoothed.

Uses & applications

Used extensively in construction for house building, paving, and decorative garden features. Also used as a material for grindstones.

Geological facts

Sandstone holds a record of the past environment it was formed in; ripple marks and cross-bedding can indicate prehistoric water or wind direction. It is a major reservoir for groundwater and oil.

Field identification & locations

Identify by its gritty, sandpaper-like feel and visible grains of sand. Common in sedimentary basins worldwide. For collectors, look for unique weathering patterns or fossils within the layers.