Mined only in Southern Alberta, Canada, Ammolite is unique to a geological deposit known as the Bearpaw Formation. The limited areal extent of this region the primary reason why ammolite is so rare. An official gemstone since 1981, Ammolite comes from the fossilized shell of ancient marine mollusks, called Ammonites, that lived in the Bearpaw Sea approximately 75 to 70 million years ago. A unique fossilization history has resulted in the breathtaking colours that adorn this captivating gem. Gem-quality Ammolite produces a spectacular display of iridescent colour when it is observed in reflected light. The colours of an individual stone can run the full range of the visible spectrum or be limited to just one or two coulors. The color display can rival fine opal and labradorite in its intensity and beauty.
The unusual formation of Ammolite on an extinct creature means the possibility of it ever being lab-created, like other gemstones such as diamonds, is minimal. The colour-producing shell layer of Ammolite is usually very thin (often less than one millimeter) and attached to a dark gray to brown base of shale or siderite. Exceptional pieces can be cut into gems without stabilization. Most Ammolite is used to produce triplets. These are made by backing the fragile iridescent material with a thin slab for stability and topping it with a transparent cover for protection.