fossil

Fossilized Gastropod Shell

Gastropoda (Class) replacement / internal cast (steinkern)

AI-generated identification · may be incorrect

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 July 27, 2026More fossil →

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Physical properties

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.