Rock Identifier
Belemnite Guard (Belemnitida rostrum) — fossil
fossil

Belemnite Guard

Belemnitida rostrum

AI-generated identification · may be incorrect

Hardness of 3-4 on the Mohs scale, typically brown to grey-white in color, with a fibrous calcite composition and a solid, bullet-like cylindrical structure.

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Physical properties

Hardness of 3-4 on the Mohs scale, typically brown to grey-white in color, with a fibrous calcite composition and a solid, bullet-like cylindrical structure.

Formation & geological history

Formed during the Mesozoic era when internal calcified squid-like fossils became mineralized in marine sediment.

Uses & applications

Valued as a geological index fossil and collected by enthusiasts worldwide.

Geological facts

Commonly known as 'thunderstones' in folklore, ancient people believed they fell from the sky during lightning storms.

Field identification & locations

Easily identified by its distinctive bullet shape and pointed tip, frequently found in chalk and limestone deposits across Europe and North America.

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