sedimentary

Red sandstone (likely iron-stained quartz sandstone)

Quartz arenite to arkosic sandstone; predominantly SiO₂ with iron-oxide coatings (hematite/goethite)

AI-generated identification · may be incorrect

Typically Mohs 6–7 for quartz grains, but the rock breaks variably along cemented grain boundaries. The specimen is reddish-brown to gray, dull to slightly gritty, fine- to medium-grained, and appears massive rather than crystalline; iron oxides provide the red coloration.

Identified September 19, 2026More sedimentary →

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At a glance

Common name: Red sandstone (likely iron-stained quartz sandstone)
Scientific name: Quartz arenite to arkosic sandstone; predominantly SiO₂ with iron-oxide coatings (hematite/goethite)
Category: sedimentary
Identified: September 19, 2026
Method: Standard

AI Estimated Value

Usually $1–$10 as a loose common specimen; roughly $10–$30 if unusually attractive, locality-labeled, or cut.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed when sand accumulated, compacted, and was cemented by silica, carbonate, or iron oxides, commonly in rivers, deserts, or alluvial fans. Its exact geological age cannot be determined from the photograph; red beds range from Precambrian to modern formations.

Uses & applications

Used as building stone, paving, aggregate, and architectural sandstone; attractive pieces may be collected or cut and polished, though this specimen appears ordinary.

Geological facts

The red pigment is usually microscopic hematite rather than abundant metallic hematite crystals. Gray weathering and reddish fresh surfaces can reflect changing oxidation conditions during or after burial.

Field identification & locations

Look for visible sand grains, gritty texture, bedding, and possible quartz-rich composition; a streak test, acid test, and hand lens help distinguish it from red volcanic rock or iron-rich metamorphic rock. Common worldwide in continental red-bed formations.