Sandstone (with potential iron-oxide weathering)

Physical Properties

Hardness: 6-7 on Mohs scale (due to quartz grains); Color: Tan, brown, or buff with darker weathering crust; Luster: Dull to earthy; Crystal structure: Clastic (granular); Cleavage: None; Specific gravity: 2.2-2.8

Formation & Geological History

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments. Occurs in desert, river, and marine environments over millions of years through lithification.

Uses & Applications

Commonly used as a building material, in construction aggregate, for paving, and as an aquifer for groundwater or reservoir for petroleum.

Geological Facts

Sandstone accounts for roughly 20 to 25 percent of all sedimentary rocks on Earth. The famous red rock formations in Sedona, Arizona and Petra, Jordan are primarily sandstone.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible layering or bedding planes. Often found in outcrops where historical water or wind flow occurred.

Identified on: 5/5/2026

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