Rainbow Fossil Ammolite - Gem Quality Ammonite Fossil Fragment

Please Note: ALL ammolite specimens will exhibit multiple colors depending on the angle of the light. The color choices reflect the dominant color of each piece.

Above: Front of Specimen Card

Ammonites are an extinct group of cephalopods that entered the fossil record 400 million years ago.  They survived several mass extinction events, including the Permian–Triassic "Great Dying" which wiped out 96% of all marine species.  They finally succumbed during the Cretaceous-Paleogene extinction event 66 million years ago, which also wiped out the dinosaurs.

As with other mollusks, the shells of ammonites had an inner layer known as the nacre or "mother of pearl". The nacre is rich in aragonite, a crystal form of calcium carbonate, which produces an iridescent sheen. Over tens of millions of years, aragonite tends to convert to calcite, the most stable form of calcium carbonate. However, in the Bearpaw Formation, the fossils have undergone a unique process of mineralization that both preserved and intensified the natural aragonite resulting in a colorful gemstone we call Ammolite.

This specimen is a large fragment of ammolite from the Bearpaw Formation of southern Alberta, Canada. The specimen comes inside a classic, glass-topped riker display case measuring 4 1/2" x 3 1/2". A small information card is also enclosed that also serves as the certificate of authenticity.

IMPORTANT NOTE ON COLOR: Ammolite comes in a wide variety of colors and the colors shift depending on the angle of the ambient lighting. We have classified these specimens based on their dominant color, but please know that all specimens will exhibit multiple colors.

Each specimen is unique in size, shape, and thickness. They are also coated in a layer of acrylic enamel. This coating protects the iridescent sheen and enhances the shine.

 Above: "Multicolor" in-hand