sedimentary

Red sandstone fragment

Quartz-rich sandstone, likely ferruginous arkose or subarkose

AI-generated identification · may be incorrect

Fine- to medium-grained, reddish-brown, dull to slightly sparkly from quartz; composed mainly of quartz with feldspar and iron-oxide cement. Hardness is about 6–7 for individual grains, with variable porosity and no cleavage; the irregular break and visible grains suggest sandstone.

Identified September 8, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when sand accumulated, was compacted, and cemented—probably in a river, dune, or floodplain setting. Its exact geological age cannot be determined from the photograph; red coloration commonly results from oxidation of iron-bearing minerals during burial or weathering.

Uses & applications

Used as building stone, paving, aggregate, and decorative stone; attractive pieces may be collected, but this fragment is unlikely to have jewelry value.

Geological facts

The rusty color is typically hematite or limonite coating the grains. Sandstone commonly preserves cross-bedding, ripple marks, fossils, or ancient environmental clues.

Field identification & locations

Look for gritty texture, visible sand-sized grains, porous areas, and layers or cross-bedding; it should feel rough rather than glassy. Common worldwide, especially in red-bed basins such as the Colorado Plateau, western United States, and comparable continental formations.