A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 130 mm (5.12 inches) wide and the ammonite measures 75 mm, which is a good size for this species. The shell sits in the original limestone matrix in which it was found. The ammonite is very well preserved and has been prepared out of the rock to reveal the shell. The shell displays some beautiful multi-coloured iridescence with different colours that appear as the viewing angle changes, with red and copper tones dominating. The shale is thin, making this a good drawer specimen.
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 90 grams.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.