fossil

Gastropod Fossil (Steinkern)

Class Gastropoda (internal mold)

Hardness: 3-4 (calcite/limestone based); Color: Tan, beige, or off-white; Luster: Dull/Earthy; Structure: Spiral or coiled planispiral/helicoid shape; Cleavage: None (fractures like stone).

Hardness: 3-4 (calcite/limestone based)
Color: Tan, beige, or off-white
Luster: Dull/Earthy

Identified July 19, 2026More fossil →

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Physical properties

Hardness: 3-4 (calcite/limestone based); Color: Tan, beige, or off-white; Luster: Dull/Earthy; Structure: Spiral or coiled planispiral/helicoid shape; Cleavage: None (fractures like stone).

Formation & geological history

Formed through permineralization or as an internal cast (steinkern) when sediment filled a snail shell which later dissolved. They are found in sedimentary layers ranging from the Paleozoic to Cenozoic eras.

Uses & applications

Used primarily for educational purposes, scientific study of paleoenvironments, and as collector items. Larger or more colorful specimens may be used in jewelry.

Geological facts

Gastropods are one of the few groups that have successfully occupied seawater, freshwater, and terrestrial habitats. The internal mold shown here is often called a 'stomach-foot' fossil because of the Greek origin of the name Gastropoda.

Field identification & locations

Identify by looking for a distinct spiral or whorled pattern that mimics a snail shell. Often found in limestone outcrops, road cuts through sedimentary rock, or dried riverbeds.

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