Ammonite

About it

Coiled, chambered shells whose chamber walls meet the outer shell in frilly, branching suture lines, unlike a nautiloid's simple curves. England's Jurassic Coast, Yorkshire, Madagascar, and Morocco supply many.

Type

Fossil (mollusc)

Group

Cephalopod (mollusc)

Colours

grey, brown, cream, black, orange, iridescent

Transparency

opaque

Periods

Triassic, Jurassic, Cretaceous

Typical values: real specimens vary. For more, see mindat.org.