sedimentary/metamorphic

Rounded brown river pebble, likely sandstone or iron-rich quartzite

Probable ferruginous sandstone; possibly quartzite (SiO₂-rich)

AI-generated identification · may be incorrect

Brown, opaque, fine-grained and water-rounded with dull earthy to slightly sugary luster; likely hardness 5–7 Mohs, with no visible cleavage. Exact identification is limited by the image; a streak, acid, and hardness test would help.

Identified August 16, 2026More sedimentary/metamorphic →

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Physical properties

Formation & geological history

Likely weathered from a sandstone or quartz-rich metamorphic outcrop and rounded by stream, beach, or glacial transport. Its age cannot be determined visually and depends on the source formation.

Uses & applications

Common pebbles have little commercial value, but quartzite may be used as aggregate, paving stone, or decorative landscaping material; attractive examples are sold as curios or polished stones.

Geological facts

The rusty color probably comes from iron-oxide staining, such as hematite or limonite, rather than abundant metallic minerals.

Field identification & locations

Look for gritty sand-sized grains and possible layering for sandstone; a hard, sparkly, quartz-rich texture that resists scratching by steel suggests quartzite. Common worldwide in river gravels and beaches.