A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The matrix measures 122 mm (4.8 inches) tall and contains a large partial ammonite that measures 83 mm across, which is huge for this species and about as big as they get. The shell sits in the original limestone matrix in which it was found that has been shaped and has a cut-flat base to allow it to be displayed freely standing. The ammonite is very well preserved and has been prepared out of the rock to reveal the shell, which displays some beautiful iridescence that changes as the viewing angle changes, with most of the colours of the rainbow appearing at certain angles. It's rare to get this range of colours in these ammonites.
These fossils are highly sought after and very hard to find. They are preserved in the same way as the famous Canadian "Ammolite" ammonites that are turned into valuable gemstones. The fossil weighs 285 grams. These fossils make great unusual gifts and each one is totally unique.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.