A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The piece of limestone matrix measures 180 mm (7.1 inches) across and contains a single ammonite, which measures 40 mm. The ammonite is 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 a nice sheen. There are flashes of copper in the shell. The fossil weighs 382 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.