A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 82 mm (3.22 inches) across and contains two partial ammonites, the largest of which measures 36 mm (1.45 inches).
The ammonites are well preserved and have been prepared out of the rock to reveal the shells, which display some subtle iridescence that changes as the viewing angle changes, with green and blue colours present against a pearlescent background.
The shell sits in the original piece of limestone shale matrix in which it was found that has been shaped and has a cut-flat base that allows it to stand by itself for display. The whole piece weighs 112 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.