fossil

Fossiliferous Rock (Invertebrate Fossil in Matrix)

Fossiliferous limestone or shaly matrix containing skeletal fossil remains

Hardness varies between 3 to 4 on the Mohs scale for calcite-replaced fossils and matrix; color is dark gray to black with a lighter gray/white fossil impression; luster is dull to earthy; crystal structure is microcrystalline or amorphous rock matrix containing crystalline calcite fossil structures.

Identified July 28, 2026More fossil →

Explore Fossiliferous Rock (Invertebrate Fossil in Matrix) 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 through the accumulation and compaction of organic remains and fine sediments in ancient marine environments, typically dating from the Paleozoic or Mesozoic eras.

Uses & applications

Used primarily for educational study, geological research, and as collector specimens for fossil enthusiasts.

Geological facts

The curved, striated fossil feature visible in the rock resembles the impression of a cephalopod shell, brachiopod, or potentially a crinoid stem fragment preserved in cross-section.

Field identification & locations

Identify by looking for distinct biological shapes, symmetry, or internal chamber structures contrasting with the surrounding host rock. Commonly found in sedimentary outcrops worldwide.

Other fossil specimens

See all

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil

Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

sedimentary

Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

fossil

Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary

Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

sedimentary