Ammonite fossils have been found across the globe, but the gemstone variety has so far only been attributed to the Bearpaw Geological Formation in Alberta, Canada. It was classed as a gemstone by ...

Opalized ammonite fossils are some of the most unique and ... Some, but not all opalized ammonites are iridescent. This happens due to the unique optical properties of opal, which is formed ...

Based on the fossil record, ammonites came in a wide range of sizes and shapes, from smaller than an inch to as large as nine feet wide. Some ammonites had long, straight shells, while others had ...

Fossils found in the northern part of Hokkaido are a new type of ammonite, the once-ubiquitous spiral-shelled creatures that went extinct with the dinosaurs 65 million years ago, researchers said.

Ammonites were shelled cephalopods that died out about 66 million years ago. Fossils of them are found all around the world, sometimes in very large concentrations. The often tightly wound shells of ...