A stunning and perfect example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 210 mm (8.25 inches) across and contains half an ammonite shell that measures 90 mm (3.6 inches), which is large for this species. The shell sits in the original limestone matrix in which it was found which has been shaped and has a cut-flat base to allow it to stand freely by itself for display. The ammonite is very well preserved and has been prepared out of the rock to reveal the shell. The shell displays some truly stunning multi-coloured iridescence with flashes of red, gold, copper, and green that appear as the viewing angle changes.
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 525 grams.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.