On offer is a remarkably large iridescent ammolite, these don't come around often in that size! A once in a lifetime opportunity to own a true gem of a fossil. This ammolite is 21 inch or 54 cm in diameter. Ammolite is an opal-like organic gemstone that has been formed by a unique fossilization process of the shells of ammonites (marine cephalopods that went extint together with the dinosaurs). It is composed primarily of aragonite, the same mineral contained in nacre, with a microstructure inherited from the shell. It is one of few biogenic gemstones; others include amber and pearl. It is primarily found in the Bear Paw Formation that extends from Alberta to Saskatchewan in Canada and south to Montana in the USA. We present you this exceptional large specimen with a vivid array of shimmering colors. Depending on the chemical properties all primary colors are possible. In this case predominantly shades of green and red, with hints of blue and violet are present. With the help of a master blacksmith we created an elegant steel display with a marble foot. The display can be rotated and tilted to capture and reflect light from every angle, creating a dynamic visual experience designed to showcase every vibrant color. It comes with the official export permits as well as full provenance documents and a certificate of authenticity. For references see Christie's https://onlineonly.christies.com/s/sculpted-nature-fossils-minerals-meteorites/large-iridescent-ammonite-56/101771 Sotheby's https://www.sothebys.com/en/buy/auction/2025/natural-history-2/very-large-iridescent-ammonite This item can be shipped worldwide, and fully insured.