sedimentary

Crinoid Fossil in Limestone

Crinoidea fossil (stalk segments) in Calcium Carbonate (CaCO3) matrix

AI-generated identification · may be incorrect

Hardness: 3 (limestone matrix); Color: Tan, beige, or grey with white fossil inclusions; Luster: Dull/earthy; Crystal Structure: Rhombohedral (calcite crystals in fossil); Cleavage: Perfect in calcite segments.

Hardness: 3 (limestone matrix)
Color: Tan, beige, or grey with white fossil inclusions
Luster: Dull/earthy

Identified June 6, 2026More sedimentary →

Explore Crinoid Fossil in Limestone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in warm, shallow marine environments during the Paleozoic era (approx. 250-500 million years ago) through the accumulation of skeletal remains and lime mud.

Uses & applications

Educational specimens, fossil collecting, and limestone is used in cement production and construction.

Geological facts

Crinoids are often called 'sea lilies' but are actually animals related to starfish and sea urchins. The disk-like segments of the stem are known as columnals.

Field identification & locations

Identify in the field by looking for 'Cheerio' shaped rings or ribbed cylindrical indentations in sedimentary stone. Common in the American Midwest and limestone quarries worldwide.