Sandstone (Quartzose)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, beige, or light brown; Luster: Dull to earthy (sparkling quartz grains); Crystal structure: Clastic (granular); Specific gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains, primarily quartz and feldspar, in environments like deserts, riverbeds, and beaches over millions of years.

Uses & Applications

Commonly used in construction for paving and building stone, as a reservoir rock for oil and gas, and as a source of silica for glassmaking.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The famous red rocks of the Grand Canyon and Zion National Park are composed largely of various sandstone layers.

Field Identification & Locations

Identify by its gritty 'sandpaper' feel. It is found globally in sedimentary basins. Collectors look for unique banding (Liesegang rings) or fossil inclusions.

Identified on: 4/17/2026

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