Rock Identifier
Fossilized Brachiopod or Gastropod in Chert/Limestone (Phylum Brachiopoda / Mollusca) — fossil
fossil

Fossilized Brachiopod or Gastropod in Chert/Limestone

Phylum Brachiopoda / Mollusca

Hardness: 7 (if chert/quartz matrix) or 3 (if limestone); Color: Tan, brownish-green, grey; Luster: Vitreous to dull; Crystal structure: Microcrystalline or amorphous matrix with calcitic fossil remains; Cleavage: None conchoidal fracture.

Hardness
7 (if chert/quartz matrix) or 3 (if limestone)
Color
Tan, brownish-green, grey
Luster
Vitreous to dull
Identified More fossil →
Explore Fossilized Brachiopod or Gastropod in Chert/Limestone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App StoreGoogle Play

Physical properties

Hardness: 7 (if chert/quartz matrix) or 3 (if limestone); Color: Tan, brownish-green, grey; Luster: Vitreous to dull; Crystal structure: Microcrystalline or amorphous matrix with calcitic fossil remains; Cleavage: None conchoidal fracture.

Formation & geological history

Formed in ancient marine environments during the Paleozoic or Mesozoic eras through the accumulation of carbonate shells and subsequent fossilization and mineralization (silicification or calcification).

Uses & applications

Educational value, amateur fossil collecting, geological study, and decorative display.

Geological facts

Brachiopods are marine animals that resemble clams superficially, though they belong to a completely different phylum and date back over 500 million years to the Cambrian period.

Field identification & locations

Found commonly in sedimentary rock formations, riverbeds, and glacial tills worldwide. Look for symmetrical shell impressions or spiral structures embedded in weathering rock.

More like this

Other fossil specimens

Crinoid Stem Fossil in Matrix (Phylum Echinodermata, Class Crinoidea) — fossil

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil
Sedimentary Outcrop (Sandstone/Shale) (Sedimentary bedrock formation (variable composition)) — sedimentary

Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary
Chert with Fossil Brachiopod (Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion) — 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

Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

fossil
Fossiliferous Limestone (Limestone with embedded fossil cross-section) — sedimentary

Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary
Fossiliferous Limestone with Crinoid stems (Limestone (CaCO3) containing Crinoidea fossils) — sedimentary

Fossiliferous Limestone with Crinoid stems

Limestone (CaCO3) containing Crinoidea fossils

sedimentary