A stunning example of a highly pyritised ammonite fossil of the species Eteoderoceras (Eoderoceras) armatum from the world-famous Jurassic Coast beach of Charmouth, Dorset UK.
The fossil measures 31 mm (1.2 inches) across. The ammonite is well preserved with strong ribbing and suture lines. It is clean on both sides with no matrix, which is unusual for these ammonites.
These are very popular ammonites and examples like this are uncommon these days.
These Eteoderoceras ammonites are often called the "king of pyrites" as they are the largest and most impressive pyrite ammonites found on the Jurassic Coast.
Around 196 million years old, this fossil would make a wonderful addition to any collection.