sedimentary

Weathered conglomeratic sandstone

Polymictic conglomerate or pebbly sandstone, likely iron-stained

AI-generated identification · may be incorrect

Coarse, rounded to subrounded clasts appear cemented in a reddish-brown matrix, with abundant iron-oxide staining and possible quartz-rich material. Typical hardness is about 6–7 for quartz grains, but the rock is variable; earthy to dull luster, no consistent cleavage, and approximate specific gravity 2.3–2.7.

Identified September 2, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when gravel and sand were deposited by a high-energy stream or shoreline, then lithified by compaction and cementation. Its precise geological age cannot be determined from the photograph; the handwritten note may indicate a local lake-bed or gravel-bed context.

Uses & applications

Used locally as aggregate, riprap, landscaping stone, and occasionally as a distinctive building or decorative stone. Ordinary hand specimens generally have little commercial value.

Geological facts

The rounded clasts indicate transport before burial, while red and orange colors commonly result from oxidized iron minerals such as hematite or goethite.

Field identification & locations

Look for visibly rounded pebbles embedded in a finer matrix and a gritty fracture surface; acid testing can reveal carbonate cement if it fizzes. Common in stream channels, alluvial deposits, shorelines, and conglomerate-bearing sedimentary formations.