sedimentary

Sandstone (or Siltstone)

Sedimentary Arenite / Siltstone

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale (quartz grains); Color: Buff, tan, to pale yellowish-grey; Luster: Dull, earthy; Grain size: Fine-grained to silty; Structure: Thinly laminated/stratified bedding visible along the break edges; Specific Gravity: 2.2 - 2.8

Hardness: 6-7 on Mohs scale (quartz grains)
Color: Buff, tan, to pale yellowish-grey
Luster: Dull, earthy

Identified October 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the compaction and cementation of mineral particles (primarily quartz and feldspar) deposited in low-to-moderate energy sedimentary environments such as floodplains, river deltas, shallow marine margins, or dunes.

Uses & applications

Commonly quarried and used worldwide as a building stone, flagstone, paving material, aggregate, or crushed stone. Clean quartz-rich sandstones are also used as a source of silica for glass manufacturing.

Geological facts

Sandstones make up roughly 20-25% of all sedimentary rocks on Earth. Their porous and permeable nature makes them some of the most critical reservoirs for groundwater aquifers and hydrocarbons.

Field identification & locations

Recognized in the field by its granular, gritty texture (feels like sandpaper when rubbed) and clear, visible bedding layers/laminations along the profile. Very common globally in sedimentary basins, road cuts, canyon walls, and river valleys.