fossil

Crinoid Marble

Crinoidal Limestone/Marble

Hardness: 3-4 (Mohs); Color: dark grey to black matrix with white or light grey fossil inclusions; Luster: matte to silky when polished; Structure: Bioclastic limestone; Cleavage: rhombohedral in calcite parts.

Hardness: 3-4 (Mohs)
Luster: matte to silky when polished

Identified July 4, 2026More fossil →

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Physical properties

Formation & geological history

Formed from the accumulation of skeletal remains of crinoids (sea lilies) in marine environments, predominantly during the Mississippian and Pennsylvanian periods. Many specimens underwent low-grade metamorphism to become marble.

Uses & applications

Primarily used for decorative purposes, including polished palm stones, jewelry, and tiles. Historically used in architectural cladding.

Geological facts

Crinoids are marine animals related to starfish and sea urchins. Although they look like plants (sea lilies), the fossils shown here are the cross-sections of their calcified stem segments.

Field identification & locations

Identify by looking for ring-shaped or 'doughnut' patterns within a darker stone. Often found in riverbeds or coastal areas with limestone outcrops. Reacts with weak acid (effervescence).