How we Grade and Value Ammolite
Ammolite is one of the world’s rarest gemstones, being only commercially mined in Southern Alberta, Canada. Ammolite is unique to a geological deposit known as the Bearpaw Formation of the Western Interior Seaway. The ammolite that comes from the fossilized shell of the ancient marine mollusks, called ammonites, lived in the Bearpaw Sea approximately 70 to 75 millions years ago. The unique fossilization history from this area has resulted in the breathtaking colours that adorn this captivating gem. The limited expanse of mining in this region is the primary reason why ammolite is so rare. The unusual formation of ammolite on an extinct creature means the possibility of it ever being lab created, like other gemstones such as diamonds, is minimal. With the world supply of ammolite rapidly diminishing, its value has appreciated over time. Many people now consider buying the gemstone as an investment. Ammolite has been an official gemstone since 1981, and the official Alberta Gemstone since March 31, 2022. The process of valuing ammolite varies slightly from other gemstones, so read on to find out more about how the Ammolite Canada prices ammolite.
1. Grade
One of the most important elements impacting the price of ammolite is its grade. Whilst the ammolite industry does not have a universal grading method, Ammolite Canada grades gemstones based on the system used by the International Gem Society (IGS). This system grades based on factors such as colour, iridescence, chromatic shift and the rotational range of colour. The highest grade of ammolite by this system is AA, followed by A+, A and A-. Some other companies describe the highest quality of ammolite as ‘AAA grade’ but this is not a grade according to the IGS standards. Therefore, it is not used by the Ammolite Canada to describe top-quality ammolite.
To achieve the AA grade status, the ammolite gemstone must meet certain criteria. It has to have at least three colours: one from the blue, green and red family. Orange and yellow shades are categorized under the red group and purple is included within the blue. To be top-grade, the stone must also be naturally bright and have no dark areas.
The chromatic shift of the stone is also important. AA grade ammolite has what is called a spectrochromatic shift, which is when the colours of the gemstone shift through the entire spectrum depending on the viewer’s perspective and the angle of light. Lower grade gemstones may show dichromatic shift, when blue will shift to green for example. Some ammolite material will just show monochromatic shift, where the colour shift remains within the same colour family, such as different shades of red.
The rotational range of colour is also a main factor in determining the grade of a gemstone. To be an AA grade stone, vibrant colour must be visible through 360 degrees of rotation. Lower quality gemstones may show a decrease in brightness when rotated, where the colour darkens or turns to black. This occurs due to natural inclusions in the ammolite which block the light.
Ammolite Canada only uses high-quality ammolite for our jewellery pieces, mostly of AA or A+ grade.
2. Size
Size is another key factor in the valuation of a piece. A larger gemstone or more gem-grade ammolite on an art piece or fossil will obviously have a higher price tag. Unlike other gemstones, such as diamonds and rubies, ammolite is not often measured by carat weight. This is because ammolite is very thin, being only about the thickness of your nail, and consequently does not weigh much. Therefore, the surface area of the ammolite is often used instead.
3. Paleontological Features
Jewellery, fossils and art pieces that show unique, paleontological features are often considered to be more valuable. For example, the fossilized shell of the ammonite can sometimes show the complex pattern of suture lines that once covered the outside of the creature. Very rarely these suture patterns can be seen in the colour of the ammolite. Gemstones with such sutures are highly valued. Take a look at some of our beautiful pieces that show these coloured sutures!
We hope this blog post helps you understand how ammolite is valued here at Ammolite Canada. If you are considering buying a piece of ammolite, now is a great time to purchase, as prices only continue to rise as supply diminishes. As a member of the Ammolite Canada team is licensed to mine for the ammolite gemstone, our customers benefit from our mine direct prices. Unlike other companies, our ammolite gemstones are also produced in Canada.