sedimentary
Crinoid and Coral Fossils in Limestone
Fossiliferous Limestone with Rugosa (order) and Crinoidea (class)
Hardness: 3-4 (Mohs); Color: Grey, tan, or charcoal; Luster: Dull/Earthy; Structure: Visible honeycomb-like coral patterns and disc-like crinoid stem fragments embedded in a fine-grained matrix.
- Hardness
- 3-4 (Mohs)
- Color
- Grey, tan, or charcoal
- Luster
- Dull/Earthy
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Physical properties
Hardness: 3-4 (Mohs); Color: Grey, tan, or charcoal; Luster: Dull/Earthy; Structure: Visible honeycomb-like coral patterns and disc-like crinoid stem fragments embedded in a fine-grained matrix.
Formation & geological history
Formed in shallow, warm marine environments where biological debris accumulated and was buried and lithified over millions of years, typically during the Paleozoic Era (485-252 million years ago).
Uses & applications
Primarily used for geological study, education, fossil collecting, and occasionally as decorative stone or garden ornaments.
Geological facts
This specimen contains 'honeycomb' patterns likely from colonial rugose or tabulate corals and segmented sections representing crinoids, often called 'sea lilies' which are animals related to starfish.
Field identification & locations
Identify by looking for repeating geometric patterns (pentagons/hexagons) and circular stem cross-sections. Commonly found in riverbeds or outcrops in areas with Paleozoic bedrock.
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