sedimentary

Turritella (Gastropod Fossil)

Turritella (Genus of gastropods), CaCO3 (Calcium Carbonate or Silicified Agate)

AI-generated identification · may be incorrect

Hardness: 3-4 (if calcite) or 6.5-7 (if silicified); Color: Cream, tan, or grey; Luster: Dull to vitreous; Structure: High-spired conical shell (turriform); Cleavage: None/Conchoidal.

Hardness: 3-4 (if calcite) or 6
Color: Cream, tan, or grey
Luster: Dull to vitreous

Identified March 29, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (if calcite) or 6.5-7 (if silicified); Color: Cream, tan, or grey; Luster: Dull to vitreous; Structure: High-spired conical shell (turriform); Cleavage: None/Conchoidal.

Formation & geological history

Formed through the accumulation of marine snail shells in sedimentary layers (limestone or sandstone), often silicified over millions of years. Most common specimens range from the Cretaceous to the Eocene period (approx. 50-100 million years old).

Uses & applications

Used primarily for fossil collecting, educational teaching sets, and in decorative lapidary arts (e.g., jewelry or bookends when found in 'Turritella Agate' blocks).

Geological facts

Despite being called 'Turritella Agate' in the trade, the famous Wyoming specimens are actually an extinct freshwater snail called Elimia tenera, though the name Turritella is still widely used in geological circles.

Field identification & locations

Identify in the field by the distinct spiral screw-like shape and visible whorls. Often found in fossiliferous limestone beds or eroded out of sedimentary cliffs near ancient shorelines.