A stunning and perfect example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 155 mm (6.1 inches) tall and the ammonite measures 91 mm, which is a good size for this species. The shell sits in the original limestone matrix in which it was found, which is relatively thin (about 8 mm thick). The ammonite is very well preserved and has been prepared out of the rock to reveal the shell. The shell displays some beautiful multicoloured iridescence with flashes of gold and copper that appear as the viewing angle changes. Please note - this fossil does not stand on its own due to the thinness of the shale matrix.
These fossils are highly sought after and very hard to find, especially complete like this. They are preserved in the same way as the famous Canadian "Ammolite" ammonites that are turned into valuable gemstones. The fossil weighs 235 grams.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.