sedimentary

Sandstone (lithic wake or graywacke)

Clastic sedimentary rock (primarily quartz and lithic fragments)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs); Color: Grey, brownish-grey; Luster: Dull/Earthy; Structure: Clastic, fine-to-medium grained; Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 (Mohs)
Color: Grey, brownish-grey
Luster: Dull/Earthy

Identified July 7, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Grey, brownish-grey; Luster: Dull/Earthy; Structure: Clastic, fine-to-medium grained; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & geological history

Formed from the accumulation and cementation of sand-sized mineral grains and rock fragments. This specific type likely formed in a marine environment or river delta where sediments were deposited and compressed over millions of years.

Uses & applications

Commonly used as construction material, road base, landscaping rock, and occasionally for structural building stones or grindstones.

Geological facts

Sandstone accounts for about 20% of all sedimentary rocks on Earth. It is a major reservoir for groundwater, oil, and natural gas due to its porosity.

Field identification & locations

Identify by its gritty texture (feels like sandpaper when rubbed) and visible grains. Often found in riverbeds, canyons, and coastal cliffs. Look for layering (stratification) in larger outcrops.