A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 91 mm (3.6 inches) across and contains a single ammonite that measures 42 mm (1.7 inches). 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 beautiful iridescence that changes as the viewing angle changes, with green and blue colours dominating. These are the most sought-after colours in these fossils and this example is as good as they get. The whole piece weighs 133 grams.
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.