A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 105 mm (4.1 inches) across and contains a single complete ammonite that measures 84 mm (3.3 inches), which is large for this species. 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 truly stunning iridescence that changes as the viewing angle changes, with most of the colours of the rainbow present, including deep green, red, copper, and gold colours. These are very sought-after colours in these fossils and this one is about as strong as these colours get! The whole piece weighs 188 grams. A real one-off fossil.
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. 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.