Late 19th century French Dragon or Chimaera pendant. These seems to have originated in France towards the end of the 19th century and were copied in England and America. Much cheaper stamped ones were made, but this is one of the best quality examples, being heavily cast and chased on both sides, with French 18 carat control marks on the pendant ring. It is set with a small old-mine cut diamond in the mouth.
It is approximately 1 inch: 27mm across, and weighs 10 grams