Iridescent Desmoceras Cretaceous Ammonite

Description: This fine ammonite is Desmoceras from Madagascar which has much of the original iridescent shell present. This is a consequence of light passing through the various layers of aragonite and conchiolin deposited by the ammonite in life. The lack of acidity in the depositional environment allowed them to be preserved as you see it here. Notice the play of colors when the viewer’s aspect changes. Please see my other offerings for an example of a specimen that has had the out shell polished away to reveal the delicate suturing pattern.