A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The piece of limestone matrix measures 45 mm (1.8 inches) across and contains a single ammonite that measures 13 mm (0.5 inches), making this a tiny juvenile of the species.
The ammonite is very well preserved and has been prepared out of the rock to reveal the shell, which displays some stunning iridescent colours that change depending on the angle that the fossil is viewed at. There is a lovely mix of green and gold colours in the shell.
The shell sits in the original thin piece of limestone shale matrix in which it was found that has a cut-flat base to allow it to be displayed freely standing. It weighs 32 grams.
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.