sedimentary

Fossiliferous Limestone (with Crinoids)

CaCO3 (Calcium Carbonate)

AI-generated identification · may be incorrect

Hardness: 3 (Mohs scale), Color: light gray to tan with darker fossil inclusions, Luster: dull/earthy, Crystal Structure: Trigonal/Hexagonal (calcite matrix), Cleavage: Perfect rhombohedral in calcite, Specific Gravity: 2.71

Identified February 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in warm, shallow marine environments through the accumulation of skeletal remains and organic debris. These fossils often date from the Paleozoic era (Carboniferous to Permian periods).

Uses & applications

Used in construction as a building stone or road aggregate, in the manufacture of cement, as a decorative garden stone, and for educational geological collections.

Geological facts

Crinoids are also known as 'sea lilies,' though they are animals related to starfish rather than plants. Their fossilized stem segments are sometimes called 'Indian beads.'

Field identification & locations

Identify in the field by looking for distinct circular or star-shaped fossil segments. It will react and fizz strongly when exposed to a drop of weak acid (like vinegar) due to the calcite content.