sedimentary

Weathered iron-rich pebble

Likely ferruginous sandstone or ironstone; exact identification requires testing

AI-generated identification · may be incorrect

Tan-brown, fine-grained, dull earthy luster, rounded by abrasion, with a pale gray-white crust or possible cement-filled cavity. Likely hardness about 4–6 Mohs and moderate-to-high density; no visible crystal cleavage.

Identified August 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably formed as sand or sediment cemented by iron oxides, then chemically weathered and rounded in a stream, beach, or glacial deposit. Its precise age and setting cannot be determined from the image alone.

Uses & applications

Primarily a natural curiosity or teaching specimen; ironstone may be used locally as aggregate or low-grade iron ore, but this small piece has negligible industrial value.

Geological facts

The rusty color commonly comes from hematite and goethite coatings. The light patch could be quartz, calcite, weathered feldspar, or simply an altered surface, so acid and hardness tests would help.

Field identification & locations

Look for a reddish-brown streak, gritty texture, and possible attraction to a strong magnet if magnetite is present; calcite would fizz in dilute hydrochloric acid. Common in weathered sedimentary terrains worldwide.