Preserved fragments of ammonite shell, bursting with irridiscence.
Anmonites evolved in aragonite seas and had aragonitic shells. Their shells consisted of three layers, which served different functions and are structurally different. The middle layer is nacre, or mother of pearl. Ammonite nacre can preserve well in the right conditions, and is sometimes also present on commercial Madagascan ammonites, however ammolite refers specifically to preserved ammonite nacre from Alberta in Canada. Ammolite is recognised as a gemstone and is generally treated to prevent cracking and discoloration.
2g. This photograph is of the item offered for sale.