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 23 mm (0.9 inches) across, which is small for this species making it a juvenile. The ammonite is well preserved on both sides with detailed suture lines, ribbing, and spine tubercles. It has a lovely pyritic colour and shine and some very unusual distortion in the outer whorl where it was compressed into the centre of the shell prior to fossilisation.
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.