sedimentary

Red Sandstone / Mudstone Nodules (L Liesegang rings)

Sedimentary Rock (Quartz/Hematite Clay Mix)

AI-generated identification · may be incorrect

Mohs hardness 2-6 depending on cementation, reddish-brown to pinkish-tan coloration due to iron oxides (hematite), earthy to dull luster, fine-grained clastic texture, no prominent cleavage.

Identified July 23, 2026More sedimentary →

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Physical properties

Mohs hardness 2-6 depending on cementation, reddish-brown to pinkish-tan coloration due to iron oxides (hematite), earthy to dull luster, fine-grained clastic texture, no prominent cleavage.

Formation & geological history

Formed by the accumulation and compaction of mineral particles or rock fragments, cemented together by silica, calcite, or iron oxide. The reddish coloration indicates deposition in an oxygen-rich continental environment, such as river floodplains or desert dunes.

Uses & applications

Used as decorative garden stone, building stone, dimension stone, or as specimens for educational collections.

Geological facts

Red sedimentary rocks get their distinctive rusty-red color from minute amounts of hematite coating the individual sand or silt grains. The concentric banding often seen in such rocks is caused by Liesegang ring formation via chemical precipitation.

Field identification & locations

Identified in the field by its fine grain, earthy feel, reddish-brown iron staining, and soft-to-medium hardness. Commonly found in sedimentary basins worldwide, including the American Southwest and parts of Europe.