The gemstone ammolite is cut from the fossilized shells of extinct sea creatures called ammonites and is found in one very specific part of Canada. (Photo credit: Kumiko Flikr)
There’s a gemstone that’s garnering more attention that could speak to those who not only like gemstones with provenance but also with a pretty cool back story.
Ammolite, the iridescent gemstone that’s actually cut from the fossilized shells of a prehistoric creature, comes from only one source only.
The gems have a truly fascinating story; here are five things you should know about them.
1. Nomenclature is key. There’s a difference in the names when it comes to gem versus fossil.
According to the GIA’s Gems & Gemology, ammonites were squid-like creatures with sharp, beak-like jaws, a spiral shell and tentacles. They went extinct about 66 million years ago.
Ammolite, meanwhile, is the trade name for the iridescent, nacreous layer of the shell of fossilized ammonite. Commercial quantities of gem-quality ammolite are only known to come very a few specific types of ammonite shells, the G&G article said.
The GIA said that a number of things must happen for ammonite to become an ammolite gem. It has to be buried quickly, deprived of oxygen, protected from heat and excessive weight, and not be scavenged.
“Ammonoid,” paleoartist Heinrich Harder’s (1858-1935) reconstruction of ammonites as they would have appeared. (Image in public domain)
2. They only come from one place. The ammonite sea creatures were around long before there were seven continents. According to the GIA, there were only two large landmasses--Gondwana and Laurasia--on the Earth’s surface when they lived.
This helps explain how the water mass in which they lived (the Bearpaw Sea) during the Late Cretaceous period now is a rock formation that stretches through Montana, and Alberta and Saskatchewan, Canada.
While fossilized ammonites can be found in several places around the world, a small area within the Bearpaw Formation, the name for the area leftover from where sediment settled on the bottom of sea, in Southern Alberta, Canada, is the only location where they have been turned into gemstones.
The International Gem Society estimates that only about 5 percent of the ammonites found in Alberta have suitable gem material on the shell surface.
3. They are fairly new to the gem and jewelry world. Despite their historic formation, ammolite is one of the few new natural gems to be introduced into the market in the past 70 years.
It only started to appear in jewelry in the 1960s and was recognized as an organic gemstone in 1981 by the
Coloured Stones Commission of the World Jewellery Confederation (CIBJO), according to the GIA.
And like tanzanite and sugilite--introduced to the trade in 1967 and 1980, respectively--ammolite occurs in large enough quantities to make it “economically significant,” Gems & Gemology said.
Ammolite earring and necklace set from Korite International 4. They vary in color and some colors are more valuable. Ammolite can come in any color in the rainbow but most are green and red. Blue and violet are rare and, typically, more valuable.
As is true for most gems, cost depends greatly on the color, which is graded on a scale from one to five. The brightness of the gem also is judged.
Ammolite also can show patterns of fractures on the surface, like stained glass. The GIA said that while fracture ammolite was common in the past, production today mostly includes sheet ammolite.
5. Demand is expected to increase. Korite International in Canada, the largest supplier of ammolite, said that it will quadruple the size of production within the next 12 months as more consumers across the world start to discover and buy the gemstone.
According to a local news story, the company currently is mining two acres a year but will expand to eight over the next year. Production is expected to increase from the current eight million carats per year, which already was increase over last year, to double within the next two years to meet demand across the globe.
The company even has targeted the United States as one of the markets where it believes ammolite could do well.
Brecken Branstratoris the senior editor, gemstones at National Jeweler, covering sourcing, pricing and other developments in the colored stone sector.
