AMMOLITE

I recently was given a wonderful gift of some spectacular Ammolite rough.  Here are a few pieces that I have started to process.  Each is about the size of a quarter.

Ammolite is a very rare opal-like gemstone found primarily in Alberta, Canada.  It may well be the rarest gemstone on earth, as rare as genuine red diamonds.

Ammolite is the fossilized shells of Ammonites, which are composed of aragonite, the same material as pearls.

Ammonites were spiral disc shaped cephalopods that once lived in tropical inland seas, becoming extinct along with the dinosaurs about 65 million years ago at the end of the Mesozoic era.

The iridescent opal-like color play of Ammolite is caused by the interference with the light which rebounds from the very thin stacked layers of aragonite platelets.  Reds and green are most common, but all colors of the spectrum are possible.  Thicker layers of platelets produce the reds and greens, thinner layers of platelets the blues and violet at the other end of the visible spectrum.

The Ammolite layer is a very thin sheet, often not more than 0.5mm thick and is usually backed with its dark gray to brown shale matrix.

Because Ammolite is relatively soft for a gemstone (4.5-5.5 on the Mohs scale) and the very thin mica-like platelet layers are subject to flaking, it is common for Ammolite to be treated with epoxy or polyester resin to harden and stabilize the material prior to cutting and polishing and to be made into doublets and triplets with a clear quartz cap to protect the delicate Ammolite from damage.

Look for reverse doublets and triplets of this spectacular gemstone in my on-line store soon.