sedimentary

Sandstone (Calcareous Sandstone)

Calcareous Sandstone (primarily SiO2 with CaCO3 cement)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (grains), 3 (cement); Color: Tan, buff, or light brown; Luster: Dull/Earthy; Crystal Structure: Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6
Color: Tan, buff, or light brown
Luster: Dull/Earthy

Identified April 9, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (grains), 3 (cement); Color: Tan, buff, or light brown; Luster: Dull/Earthy; Crystal Structure: Clastic; 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 specimen shows signs of water-erosion, suggesting it was likely deposited in a riverbed or coastal environment.

Uses & applications

Used widely in construction as a building material, grit for glass making, and as a decorative stone in landscaping.

Geological facts

Sandstone represents about 20-25% of all sedimentary rocks on Earth. Its porous nature makes it a crucial reservoir rock for groundwater, oil, and natural gas.

Field identification & locations

Identify in the field by its gritty texture (feels like sandpaper) and visible sand grains. Calcareous varieties will fizz when in contact with dilute hydrochloric acid.