A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 225 mm (8.85 inches) tall and contains a single ammonite, which measures 70 mm. The shell sits in the original limestone matrix in which it was found. The ammonite is very well preserved and has been prepared out of the rock to reveal the shell, which displays some truly stunning multi-coloured iridescence with bright green dominating. Green is the most sought after, and hardest to find, colour in these fossils. The matrix has a cut-flat base to allow it to stand freely for display either on its side or as a tall display piece. A crack in the matrix has been stabilised and there is another partial ammonite on the back that is covered in rare encrusting bivalve shells.
These fossils are highly sought after and very hard to find, especially complete like this. They are preserved in the same way as the famous Canadian "Ammolite" ammonites that are turned into valuable gemstones. The fossil weighs 550 grams.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.