Ammonite (var: Ammolite)

Item Description

Here we have a beautiful polished stone of the well-known Ammonite (var: Ammolite) from Alberta, Canada featuring the desirable "dragon skin" pattern. This techinically is not a mineral / gem but a fossil of the original Calcium Carbonate shell of the animal within. From Wikipedia: "Ammolite, is an Opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America. It is made of the fossilized shells of ammonites, which in turn are composed primarily of Aragonite, the same mineral that makes up nacreous pearls. It is one of few biogenic gemstones; others include amber and pearl. In 1981, ammolite was given official gemstone status by the World Jewellery Confederation, the same year commercial mining of ammolite began. It was designated the official gemstone of the Province ofAlberta in 2004. An iridescent opal-like play of color is shown in fine specimens, mostly in shades of green and red; all the spectral colors are possible, however. The iridescence is due to the microstructure of the aragonite: unlike most other gems, whose colors come from light absorption, the iridescent color of ammolite comes from interference with the light that rebounds from stacked layers of thin platelets that make up the aragonite. The thicker the layers, the more reds and greens are produced; the thinner the layers, the more blues and violets predominate. Reds and greens are the most commonly seen colors, owing to the greater fragility of the finer layers responsible for the blues. When freshly quarried, these colors are not especially dramatic; the material requires polishing and possibly other treatments in order to reveal the colors' full potential". This stone is a good representation of this well known and beloved material.