A stunning and perfect example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 230 mm (9.05 inches) across and contains two ammonites that measure 92 mm and 47 mm. The shells sit in the original limestone matrix in which they were found that has a cut-flat base to allow it to stand freely by itself for display. The ammonites are very well preserved and have been prepared out of the rock to reveal the shells, which display some subtle multicoloured iridescence with flashes of pink and green that appear as the viewing angle changes and an overall pearlescent sheen.
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 975 grams.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.