Ammolite, Ammolite is a rare and valuable opal-like gemstone. It is part of the fossilized shell of an ammonite, which in turn is composed primarily of Aragonite. Gem quality ammolite comes primarily from Alberta, Canada.
Ammonites went extinct with Dinosaurs 65 million years ago. Ammonites survived until the end of the Cretaceous period in a sea that covered what is now Alberta. Canada and Montana, USA. These ammonites were transformed into the rare gem known as Ammolite.
An carat Black Opal purchased by Richard Krementz in Lightning Ridge, Australia. Courtesy of Richard Krementz Gemstones. Photo by Robert Weldon/GIA (Gemological Institute of America) via Dieter Rosenkranz