Sandstone (Quartz-rich)

Physical Properties

Hardness: 6-7 on Mohs scale (due to quartz content); Color: Tan, buff, or light brown; Luster: Dull or earthy; Crystal structure: Clastic (grainy); Cleavage: None; Specific gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments, typically in environments like deserts, river deltas, or beaches. Geological age can range from Precambrian to Holocene.

Uses & Applications

Extensively used in construction as a building stone and paving material. Crushed sandstone is used in road bases. High-purity versions are used in glass manufacturing.

Geological Facts

Sandstone accounts for about 20-25% of all sedimentary rocks in the Earth's crust. It is a major reservoir for groundwater, oil, and natural gas due to its porosity.

Field Identification & Locations

Identify in the field by its gritty 'sandpaper' feel. It often exhibits visible layers (bedding planes). Collectors should look for unique cross-bedding or fossil inclusions.

Identified on: 4/17/2026

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