Sandstone (Red)

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Reddish-brown to tan; Luster: Dull/Earthy; Crystal structure: Clastic (grain-based); Cleavage: None; Specific gravity: 2.2 - 2.8.

Formation & Geological History

Formed through the accumulation and cementation of mineral particles or rock fragments (silt/sand) in high-energy environments like rivers, deserts, or shorelines. The red color indicates oxidation of iron-rich minerals (hematite) during formation, often in terrestrial lacustrine or fluvial settings.

Uses & Applications

Commonly used as a building material, decorative stone for landscaping, and as a source of high-purity silica for glass manufacturing.

Geological Facts

Red sandstone is famous for creating the iconic landscapes of the American Southwest, such as the Grand Canyon and Zion National Park. It has been used in architecture since prehistoric times due to its relative ease of carving compared to igneous rocks.

Field Identification & Locations

Identify by its gritty, sandpaper-like texture and visible layers of bedding. Found globally in basins where sediment accumulates. For collectors, look for ripple marks or cross-bedding indicating ancient water currents.

Identified on: 4/17/2026

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