Fossils Direct strive to bring the finest fossils to the open market and this is no exception ! This is the finest Gault clay ammonite with the most amazing irridescent shell exhibiting fantastic flashes of the very rare blue spectrum of colours. When the ammonite is viewed at different angles, other colours come into play which include colours from the green spectrum. Probably one of the finest displays of irridescence we have ever seen on an ammonite.