A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 143 mm (5.65 inches) across and contains two ammonites, one on each side of the matrix. The ammonites measure 100mm (3.9 inches) and 75 mm (3 inches), which is very large for this species. The ammonites sit in the original limestone matrix in which they were found that has been shaped. It is a thin piece of shale that does not stand by itself, making it an ideal drawer fossil or display fossil with a stand (not included)
The ammonites are very well preserved and have been prepared out of the rock to reveal the shells, which display some beautiful subtle iridescence that causes the colours to change as the viewing angle changes. There are deep red colours with flashes of orange, green, and gold colours against a pearlescent sheen. It weighs 545 grams. A crack in the larger ammonite has been repaired but does not detract from the beauty of the specimen.
These fossils are highly sought after and hard to find, especially large 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.