A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The piece of limestone matrix measures 140 mm (5.45 inches) across and contains a large single ammonite, which measures 47 mm (1.82 inches) across, which is big for this species.
The ammonite is very well preserved and has been prepared out of the rock to reveal the shell, which displays some subtle iridescent colours that change depending on the angle that the fossil is viewed at, with flashes of red and orange against a bronze sheen. The fossil weighs 535 grams and has a cut flat base to allow it to stand freely for display.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection. These fossils are preserved in the same way as the more famous Canadian "ammolite", which is turned into valuable gemstones due to the stunning iridescence.