Rock Identifier
Fossilized Gastropod Shell (Gastropoda (Class) replacement / internal cast (steinkern)) — fossil
fossil

Fossilized Gastropod Shell

Gastropoda (Class) replacement / internal cast (steinkern)

Hardness: ~3 (calcite) to 7 (silicified); Color: off-white to pale tan with bluish-grey core areas; Luster: dull to earthy; Structure: helical spiral/coiled shape; Cleavage: none (varies by mineral replacement).

Hardness
~3 (calcite) to 7 (silicified)
Color
off-white to pale tan with bluish-grey core areas
Luster
dull to earthy
Identified More fossil →
Explore Fossilized Gastropod Shell in the encyclopedia →

Identify your own rocks.

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

App StoreGoogle Play

Physical properties

Hardness: ~3 (calcite) to 7 (silicified); Color: off-white to pale tan with bluish-grey core areas; Luster: dull to earthy; Structure: helical spiral/coiled shape; Cleavage: none (varies by mineral replacement).

Formation & geological history

Formed through petrifaction or mineral replacement (often calcite, silica, or aragonite) of an ancient sea snail or marine gastropod shell in shallow marine or freshwater sedimentary environments during the Phanerozoic Eon.

Uses & applications

Educational specimens, private collections, lapidary display, and geological study of ancient marine environments.

Geological facts

Internal casts or steinkerns form when sediment fills the empty cavity of a shell, solidifies into rock, and the original outer shell later dissolves away, leaving a molded replica of the shell's interior.

Field identification & locations

Recognizable by its distinct spiraled or conical shape with whorls. Commonly found in sedimentary rock formations such as limestone, shale, and chalk worldwide.

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 (Fossiliferous Calcilutite / Biomicrite) — sedimentary

Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

sedimentary