Mined in Alberta, Canada, ammolite was recognized by the International Colored Gemstone Commission (ICGC) in 1981 as a new organic gemstone and is considered the rarest gemstone in the world.
The name "ammonite" is derived from the ancient Egyptian god named Ammon who believed these creatures were divine. Ammon is represented in ancient literature by the head of a ram with twisted spiral horns that are reminiscent of an ammonites spiraled shells. Pliny the Elder, the Roman historian, considered ammonite to be the holiest of stones because he believed it would summon dreams of prophesy.
Ammolite is the mineralized remains of an ammonite, the predecessor to the nautilus. This creature swam the oceans from the Paleozoic to the end of the Cretaceous era 65 to 70 million years ago and had coiled shells with chambers that filled with gas and provided both buoyancy and propulsion in the water. Although fossilized ammonites are found all over the world, supplies of the colorful iridescent gem quality ammolite are found only in southern Alberta, Canada, and only about 5% of this material actually yields gemstone material.
Ammolite forms from the mineralized remains of the ammonite shell which was exposed to tectonic pressure, mineralization, and intense heat. It is composed of 97% aragonite, 1% iron, 1% silica, and 1% trace minerals such as titanium, copper, chromium, magnesium, manganese, aluminum, barium, silicon, strontium, and vanadium.
It is aragonite that is responsible for the beautiful and intense color play in the stone. The aragonite crystals form thin scales and / or layers of various thickness and as light hits these layers it is diffracted and exhibits the intense reds, yellows, greens, blues and other colors of the rainbow seen in gem quality ammolite