A highly pyritised ammonite fossil of the species Promicroceras pyritosum from the world-famous Jurassic Coast beach of Charmouth, Dorset UK.
The fossil measures 25 mm (1 inch) across, which is huge for this species and about as big as it gets. The ammonite is very well preserved on both sides and is slightly compressed flat. The ribs are very finely defined and the pyritic colour and shine is beautiful. A great example of the species and incredible in the flesh.
These pyrite ammonites have long been used to make beautiful natural jewellery.
Around 196 million years old, this fossil would make a wonderful addition to any collection.