A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 195 mm (7.6 inches) wide and the ammonite measures 82 mm, which is large for this species. The shell sits in the original limestone matrix in which it was found that has been split to reveal both the positive ammonite shell and the negative impressed (it has been "popped" open). This is rare in these fossils as they are very hard to split like this, making it a unique example. The ammonite is very well preserved and has been prepared out of the rock to reveal the shell. The shell displays some beautiful green iridescence with flashes of gold and blue that change as the viewing angle changes. Green is the most sought-after colour on these fossils and this is one of the most colourful we have ever seen. It is a real collector's specimen that has the wow factor.
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 995 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.