Pyritized ammonite occurs during petrification, when the ammonite's organic material is replaced with pyrite! The result is a beautifully pyritized fossil.  Pyritized ammonites are truly mother natures jewels.  Every single one created by the fossilization process is unique, making this design the only one of it's kind on earth.  I had to have this fossil when I saw it and I wanted a setting that would complement the fossilized shell.  I textured the front of the backplate to mimic the crystalized pyrite and I pierced out an ammonite shape on the back.  Truly a unique piece.  It's strung on a 15" length of faceted pyrite coin beads which are not a common shape for pyrite beads.