A stunning example of an iridescent ammonite fossil of the species Caloceras johnstoni from North Somerset, UK.
The matrix measures 145 mm (5.7 inches) tall and contains a single complete ammonite that measures 75 mm (3 inches), which is large for this species. It weighs 795 grams and the matrix has a cut-flat base for display.
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 beautiful iridescence with a wide range of colours, including green, red, gold, and copper with flashes of blue that appear as the viewing angle changes. These are some of the best colours possible in these fossils and cover most of the rainbow spectrum!
A real one-off for the serious collector of fine ammonites.
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.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.