A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 103 mm (4.1 inches) across and contains two ammonites, the largest of which measures 23 mm (0.9 inch), making them juveniles of the species. The ammonites sit in the original limestone matrix in which they were found that has been shaped and has a cut-flat base to allow it to be displayed freely standing. The ammonites are very well preserved and have been prepared out of the rock to reveal the shells, which display some beautiful iridescence that causes the colours to change as the viewing angle changes. There are deep green hues in the shells, which are some of the rarest and most sought-after colours in these fossils. The fossil weighs 282 grams.
These fossils are highly sought after and hard to find, especially complete examples like this one. 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.