A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The piece of limestone matrix measures 147 mm (5.8 inches) across and contains three beautiful ammonites, the largest of which measures 48 mm. The ammonites are very well preserved and have been prepared out of the rock to reveal the shells, which display some stunning iridescent colours that change depending on the angle that the fossil is viewed at. There is a deep red shine to them with flashes of gold, green, and orange on the inner whorls. The fossil weighs 482 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.