sedimentary
Crinoid Stem Fossil (in matrix)
Crinoid (Class Crinoidea)
Hardness: 3 (calcite); Color: Tan/brown matrix with white/cream fossil; Luster: Dull to earthy; Structure: Cylindrical/discoid segments; Cleavage: Rhombohedral in crystalline parts.
- Hardness
- 3 (calcite)
- Color
- Tan/brown matrix with white/cream fossil
- Luster
- Dull to earthy
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Physical properties
Hardness: 3 (calcite); Color: Tan/brown matrix with white/cream fossil; Luster: Dull to earthy; Structure: Cylindrical/discoid segments; Cleavage: Rhombohedral in crystalline parts.
Formation & geological history
Formed during the Paleozoic era (approx. 250-500 million years ago) in shallow marine environments. These are skeletal remains of marine animals related to starfish.
Uses & applications
Primarily for educational purposes, scientific study, and as a popular item for amateur fossil collectors and jewelry.
Geological facts
Crinoids are often called 'Sea Lilies' because they resemble plants, but they are actually echinoderm animals. Individual segments of the stem are known as 'columnals'.
Field identification & locations
Identified by circular or star-shaped cross-sections and stacked disc structures. Commonly found in limestone or shale outcrops globally, particularly in the US Midwest.
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