Ammonite

Rainbow colours

These ammonites are very crushed, but show the beautiful iridescence of the aragonite shell. They come from the Somerset coast near Minehead. Iridescent ammonites like these are very rare on the Dorset coast. The fine layers that make up the shell have been preserved and they scatter light to produce the rainbow colours.

Find out more about ammonites on the molluscs pages.

Common name

Ammonite

Scientific name

Caloceras johnstoni

Type

Molluscs > Cephalopods


Strata

Blue Lias

Time period

Lower Jurassic

Age

205 million years

Where found

Somerset coast

Found by

Pete Langham

Museum

Lyme Regis Museum

Accession number

L.1986.280.10