A highly pyritised ammonite fossil of the species Eoderoceras (Eteoderoceras) armatum from the world-famous Jurassic Coast beach of Charmouth, Dorset UK.
The fossil measures 11 mm (0.45 inches) across, which is tiny for this species. The ammonite is very well preserved on both sides. The ribs are very finely defined and the pyritic colour and shine is beautiful.
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.