Sandstone or Siltstone

Physical Properties

Hardness: 6-7 (depends on cement); Color: Tan, brown, grey; Luster: Dull/Earth; Structure: Clastic, gritty texture

Formation & Geological History

Formed from the compaction and cementation of sand-sized grains over millions of years, typically in river, desert, or shallow marine environments.

Uses & Applications

Used in construction, as aggregate, and sometimes for landscaping or facing stone.

Geological Facts

Sandstone is one of the most common types of sedimentary rock and is found in sedimentary basins worldwide.

Field Identification & Locations

Identified by its gritty feel, visible sand grains, and layering (bedding). Commonly found exposed in cliffs, riverbeds, and arid regions. Collectors might look for specimens with interesting banding or fossils.

Identified on: 4/26/2026

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