fossil

Belemnite Fossil

Belemnitella sp. (rostrum)

AI-generated identification · may be incorrect

Hardness: 3.5-4 (calcite); Color: Dark grey, brown, or black; Luster: Vitreous to dull; Structure: Solid calcite bullet-shaped guard (rostrum) with radial fibers and a central canal; Specific Gravity: 2.7

Hardness: 3
Color: Dark grey, brown, or black
Luster: Vitreous to dull

Identified August 5, 2026More fossil →

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Physical properties

Formation & geological history

Formed during the Mesozoic era (Jurassic to Cretaceous periods, approximately 200 to 66 million years ago) from the fossilized internal skeleton (rostrum) of an extinct squid-like cephalopod.

Uses & applications

Used primarily in fossil collecting, educational displays, and occasionally in amateur jewelry-making or lapidary work.

Geological facts

Commonly known as 'thunderbolts' or 'devil's fingers' in folklore because people historically believed they were hurled to earth during thunderstorms.

Field identification & locations

Easily identifiable in the field by its distinct bullet or cigar shape, dark fibrous calcite composition, and tapering point. Frequently found in marine sedimentary deposits like chalk and limestone cliffs and beaches.