sedimentary

Fossiliferous Sandstone / Mudstone

Sedimentary Rock (Clastic with Fossiliferous Inclusions)

Hardness: 3.0-6.0 Mohs (varies with composition and cementation). Color: Earthy brown, tan, yellowish-brown to dark gray. Luster: Dull to earthy. Structure: Granular, bedded, or fine-grained clastic matrix with embedded organic debris. Specific gravity: 2.2-2.6.

Hardness: 3
Color: Earthy brown, tan, yellowish-brown to dark gray
Luster: Dull to earthy

Identified July 27, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation and cementation of mineral grains and small shell fragments or organic casts in shallow marine, river, or lake bed sedimentary environments over millions of years.

Uses & applications

Primarily collected as geological or paleontological samples, used in basic construction/landscaping, and studied for stratigraphic mapping and paleoenvironmental analysis.

Geological facts

Fossiliferous sedimentary rocks often capture snapshots of ancient seabed life, containing tiny crinoid stems, brachiopods, or bryozoan fragments that reveal prehistoric marine environments.

Field identification & locations

Identified in the field by its distinct layered appearance, rough grainy texture, earthy tones, and tiny visible fossil inclusions or impressions. Common in sedimentary basins, river valleys, and exposed road cuts globally.

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