fossil

Fossilized Echinoid (Sea Urchin) or Brachiopod

Echinoidea / Invertebrate Fossil

Hardness varies around 3 to 4 on the Mohs scale depending on mineral replacement (often calcite or silica). Color ranges from whitish-gray to tan. Luster is dull or earthy. Crystal structure is microcrystalline or calcitic.

Identified August 3, 2026More fossil →

Explore Fossilized Echinoid (Sea Urchin) or Brachiopod in the encyclopedia →

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Physical properties

Formation & geological history

Formed in marine sedimentary environments during ancient geological periods (such as the Paleozoic or Mesozoic eras), where the hard parts of marine organisms were buried in sediment and replaced by minerals over millions of years.

Uses & applications

Used primarily in educational displays, fossil and mineral collections, and paleontology studies.

Geological facts

Fossils like this help geologists and paleontologists date rock layers and reconstruct ancient marine environments from hundreds of millions of years ago.

Field identification & locations

Found commonly in limestone or chalk deposits. Collectors look for distinct radial symmetry or preserved shell structures.

Other fossil specimens

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

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Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

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Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

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Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary

Fossiliferous Limestone with Crinoid stems

Limestone (CaCO3) containing Crinoidea fossils

sedimentary