Rare Natural Canadian Ammolite good Cabochon ,Ammolite Gemstone For Making Jewelry, Ammolite Drop shape Superstone is carats 41.5 carats

Ammolite is a rare and valuable opal-like organic gemstone. It is found 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 several biogenic gemstones; others include amber and pearl. 
An iridescent opal-like play of color is shown, mostly in shades of green and red; all the spectral colors are possible, however. 
The iridescence is due to the good microstructure of 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.

This drop shape superstone is 41.5 carats