sedimentary

Weathered sandstone or iron-stained siltstone

Quartz-rich clastic sedimentary rock, likely ferruginous sandstone

AI-generated identification · may be incorrect

Gray-brown, fine- to medium-grained, dull to slightly earthy luster, with orange-red iron-oxide staining and prominent natural fractures. Likely hardness about 6–7 where quartz-rich; no obvious cleavage or crystal faces; apparent density roughly 2.3–2.7 g/cm³.

Identified August 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when sand or silt was compacted and cemented, probably in a shallow-water or floodplain setting. The rusty color reflects oxidation of iron-bearing minerals during weathering; exact age cannot be determined visually. Near 40.1°N, 85.4°W, sedimentary glacial deposits and locally derived bedrock are plausible.

Uses & applications

Primarily a landscaping or ordinary construction stone; attractive pieces may be used as garden rock or informal specimens. It has little jewelry value.

Geological facts

The orange-red zones are likely hematite or limonite coatings/cement rather than a distinct red mineral. Fractures and rounded edges suggest prolonged weathering or transport.

Field identification & locations

Look for visible sand grains, gritty texture, and fizz-free behavior in dilute hydrochloric acid; a streak test may produce a pale brown or reddish mark. A hand lens and fresh broken surface would distinguish sandstone from siltstone or weathered shale. Commonly encountered in glacial till, stream gravels, and sedimentary outcrops of the Midwest.