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Ammolite

Ammolite is the fossilized nacre or Mother of Pearl of the once living ammonite.    It is a very unique natural phenomenon that results in firey colors similar to opal.  Fossil ammolite is also known as aapoak, calcentine, korite, ammonite shell, gem ammolite or gem ammonite.  Ammonites, once the main predators of the ocean, became extinct 60-70 million years ago.  Their closest living relative is the modern nautilus. Over millions of years the shell has been transformed into amazing colors of ammolite that dazzle the beholder.  Similar to firey opal, the iridescent colors flash and change colors with the slightest change of viewing angle.  It is considered to be the rarest gemstone on earth and only one of three organic gemstones; the others are pearls and amber.  It is one of the very few gemstones that has not been lab created, or man made.

 

The colors in Ammolite are not caused by refraction, like most gemstones, but they result from interference with the light reflected back to the viewer from the stacked layers of thin platelets in the aragonite.  These layers that make up ammolite are very thin.  I have seen it from 1-2 millimenters to 0.5–0.8 millimeters and can actually be only hundreds of a millimeter thick, after polishing.  The thicker layers of aragonite produce red colors, while thinner layers are green, then blue, and purple.  Blues and purples are very rare and more valuable.  The thin delicate sheets in which ammolite occurs can flake and chip in their natural state and for these reasons many times the material is impregnated with a clear epoxy or other synthetic resin to stabilize ammolite prior to cutting.

 

The way the colors play when ammolite is held in your hand and rotated slightly is very dramatic.  It is absolutely stunning to see the colors change from red to green and back again.  This is called chromatic shift and rotational range.

 

Chromatic shift describes how the colors change with the angle light hitting the gem and the angle of viewing the gemstone.  The higher the grade material, the more color change you will see.

 

Rotational range relates to how far the gem or fossil (yes, whole fossils are covered with this gemstone!) can be turned while maintaining its play of color; the best rotate 360 degrees and still show color.

 

The brightness of colors and iridescence is depends on preservation of the nacreous shell, and how fine and orderly the layers of aragonite are.  Of course the quality of the polish and any impurities are also factors.  Cracking and flaking reduce the value and the most sought after ammolite has large area of colors.  Multiple bright colors being most valued. 

 

In cut gemstones, ammolite is sometimes treated like precious opal and bonded to a backing stone, or matrix.  This is termed a doublet.  Also it can be made into a triplet with three layers, the backing stone, then the ammolite and then a cap of either synthetic or natural stone including:  spinel, corundum, quartz, or glass. The cap acts as a lens and has the effect of enhancing the ammolite's iridescent display.

 

I hope that you have the opportunity to see ammolite in person.  It is one of the most beautiful things on earth.  Please visit us at our eBay store:  Cerelles-Fossils-Collectables or fossilsrare.com which is also our ebay store.

Here is where you will find gorgeous ammonites with colorful opal like ammolite. Ammonites are found around the world, but few have the iridescent mind boggling color that make these so desirable. Ammolite is a fairly new gem; the term having been coined in the 1980's. Ammolite (also known as korite, calcentine, or Buffalo Stone.) is a fossilized, opalized ammonite shell used as a gemstone (it is the shell of the ammonite, a fossilized marine animal, a cephalopod). What is Ammolite? Here is the short non-technical version from the American Museum of Natural History. Ammonites are extinct mollusks related to the modern squid, octopus and Chambered Nautilus. Under certain conditions related to fossilization, the nacreous shell becomes highly iridescent; the resulting gemlike material is called "ammolite." It is considered the rarest gemstone on earth. All of the fossils, and especially the ammonite that you find in my store are being extremely difficult to find. The mines in Madagascar are running out, and supply is very scarce. I am told that in 2 years the mines will be finished. The prices for the jewelry quality ammonites are up over 400% over the last 1-2 years! I will continue to add to this post with new information ,not only about the supply, but with the history and stories about ammonites. And, I also will discuss ammolite from Canada. http://stores.ebay.com/Cerelles-Fossils-Collectables