Sandstone (Yellow/Siltstone variant)

Physical Properties

Hardness: 6-7 Mohs; Color: Tan, yellow, light brown; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific gravity: 2.2-2.8

Formation & Geological History

Formed from the accumulation of sand-sized mineral particles or rock fragments. Over millions of years, pressure and minerals like silica or calcium carbonate cement the grains together in riverbeds, deserts, or marine environments.

Uses & Applications

Predominantly used as a construction material (flagstone, pavers) and in glass manufacturing or as a filter medium. Historically used for grindstones and sculpture.

Geological Facts

Sandstone accounts for roughly 20-25% of all sedimentary rocks on Earth. It is a major reservoir for water (aquifers) and oil/gas due to its porosity.

Field Identification & Locations

Identify by its gritty texture (feels like sandpaper) and visible layers or bedding planes. It is commonly found in canyon regions, cliffs, and dry riverbeds.

Identified on: 4/17/2026

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