sedimentary

Sandstone Cobble

Arenite (primarily SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Cream, tan, or light yellow; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Feel: Gritty like sandpaper.

Hardness: 6
Color: Cream, tan, or light yellow
Luster: Dull/Earthy

Identified July 2, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Cream, tan, or light yellow; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Feel: Gritty like sandpaper.

Formation & geological history

Formed over millions of years through the accumulation and cementation of sand-sized mineral grains, primarily quartz and feldspar, often in marine or desert environments. This specimen has been rounded by wave or wind erosion.

Uses & applications

Used in construction, as a building stone, in glass manufacturing if high in silica, and for landscaping.

Geological facts

Sandstone can preserve fossilized footprints and ripple marks from ancient riverbeds or beaches. It makes up some of the world's most spectacular natural formations like the Grand Canyon.

Field identification & locations

Identify by its gritty texture and visible sand grains. It is extremely common on beaches, in riverbeds, and in desert outcrops worldwide. Collectors look for unique banding or patterns.