sedimentary

Sandstone (Weathered Coastal Boulder)

Arenite (composed primarily of SiO2)

Hardness: 6-7 (Mohs); Color: Tan, beige, to grey with darker organic staining; Luster: Dull/Earthy; Crystal Structure: Clastic (granular texture); Cleavage: None (breaks across grains); Specific Gravity: 2.2-2.8

Hardness: 6-7 (Mohs)
Color: Tan, beige, to grey with darker organic staining
Luster: Dull/Earthy

Identified March 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments (lithification). These boulders often originate from ancient marine or river delta environments and are weathered over thousands of years by coastal erosion.

Uses & applications

Primary use in construction (dimension stone), masonry, and glass manufacturing. In a natural coastal setting, these large boulders serve as critical sea defenses and coastal stabilizers.

Geological facts

Sandstone accounts for roughly 20-25% of all sedimentary rocks on Earth. The dark coloring on the surface of this specific specimen is likely 'desert varnish' or organic algae growth from exposure to the elements.

Field identification & locations

Identify in the field by its gritty, sand-paper like feel and visible layers of bedding. Commonly found along coastlines, riverbeds, and desert regions. Look for small grain clusters and horizontal stratification lines.

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