sedimentary

Gastropod Steinkern (Fossil Snail Internal Mold)

Class Gastropoda (Internal Mold)

Hardness: 3-4 (Calcite/Sediment based); Color: Earthy tan, grey, or beige; Luster: Dull/Earthy; Structure: Coiled spiral or helical shape without external shell texture; Cleavage: None (fractures irregularly).

Hardness: 3-4 (Calcite/Sediment based)
Color: Earthy tan, grey, or beige
Luster: Dull/Earthy

Identified March 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when a snail shell fills with sediment or minerals which then harden into rock (lithification) while the original shell later dissolves away. These range from the Paleozoic to Cenozoic eras (approx. 500 million to 66 million years old).

Uses & applications

Educational tools, geological research (paleoenvironmental indicators), and popular entry-level collector items.

Geological facts

A 'steinkern' is a German word meaning 'stone kernel'. It is a common fossil occurrence where the internal cavity of a shell provides a perfect 3D cast of the animal's home even after the organic shell is long gone.

Field identification & locations

Identify in the field by looking for distinct spiral 'whorls' in sedimentary rock layers like limestone or shale. To identify, look for the absence of surface ornamentation (ribs or spines) which indicates an internal mold rather than the original shell.

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