Iridescent ammonite shells, drenched in rain at the wholesale Denver gem show. Â Ammonites may retain some of their original mother of pearl, known more technically as nacre. Â When they are wet or polished, the colors can be as vivid as opal.
These particular ammonites come from theÂ Mahajanga River Basin, near theÂ village of Ambatolafia, in the Sitampiky commune, in the Boeny regionÂ of northwest Madagascar, in the former province of Mahajanga. Â They date from the Early Cretaceous period,Â Albian age (~100 to 113.0 million years ago).
Â© 2014, Images and Text, Christopher Lee Matthews