A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 182 mm (7.15 inches) across at the widest point and contains two ammonites that measure 80 mm and 77 mm. The shells 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 stand by itself for display. The ammonites are very well preserved and have been prepared out of the rock to reveal the shell details, which display some truly beautiful multicoloured iridescence with flashes of red, gold, green, and copper that appear as the viewing angle changes. The colours are especially vivid on this specimen.
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 475 grams.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.