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 25 mm (1 inch) across. The ammonite is well preserved on both sides with detailed suture lines, ribbing, and spine tubercles. It has a lovely pyritic colour and shine.
These ammonites have long been used to make natural jewellery.
Around 196 million years old, this fossil would make a wonderful addition to any collection.