Rainbow gemstone from Canada

While there is no lack of multicolour gemstones in the market, ammolite, which captures the seven hues of the rainbow, deserves closer attention.

Ammolite has a long history but is also a very young gemstone. This organic gem comes from ammonite, an ancient creature that went extinct about 65 million years ago. Sharing a similar structure with pearl, the surface of ammolite is composed of many layers that are bound together like pages of a book. Thus rainbow colours are produced when light shines on these layers, explained M C Wong, meteorologist, ammonite fossils collector and an active member of the Mineralogy Society of Hong Kong in a recent industry seminar.

Despite its exceptional appearance, ammolite was only recognised by CIBJO as an organic gemstone in 1981 after jewellery application of ammolite was first attempted in 1962. Since more than a decade ago, Chinese feng shui master Li Kui Ming has extolled the virtues of ammolite, raising public awareness of the gemstone. Since then ammolite’s popularity has been on the increase.

According to Wong, ammolite can be found around the world but Canadian ammolite boasts the most stunning colours, thanks to the presence of unique trace elements there. Ammolite was first recorded by Commission Géologique du Canada in 1908 along St. Mary River in Alberta, Canada. Today, Canadian ammolite mines span from Calgary in Canada down to Utah in the United States. Most ammolites are found in the K Zone about 15 to 20 meters below ground level. However, the most sought after material resides in the Blue Zone located 20 to 40 meters beneath the surface.

With a hardness of Mohs 4, ammolite is often made into doublet and triplets by adding a layer of synthetic spinel or quartz in jewellery application to enhance its hardness. Another method is to apply a layer of epoxy to the ammolite before polishing. However, this only suitable for producing pendants or earrings but not for rings or bracelets due to its softness. The colourful layer of nacre in ammolite is as thin as 0.5mm so special polishing techniques are required in jewellery manufacturing, Wong explained.

Market

Since the 1970s, the price of ammolite has increased 10 fold, said Jay Maull, president of Canadian company Korite, the first and the largest commercial producer and marketer of ammolite in the world. As a result of increased exposure of the gemstone and celebrity outreach, its price leaped by 300 percent since 2008, he added. Established in 1979, Korite specialises in ammolite and ammolite jewellery. The company now operates four production facilities (one in Canada and the rest in Asia) and serves clients from 28 countries and regions around the world.

Maull said the current retail price of ammolite ranges between US$15 per square millimetre for the top grade AAA and US$0.6 per square millimetre for the lowest-ranking grade B. Regarding Korite’s production, only 10 percent reaches grade AAA. Forty percent belongs to grade AA and A and the remaining 50 percent are standard and grade B.

In terms of supply, Korite is now working on about six acres of mine, recovering about 250,000 pieces of ammolite each year. According to the company’s estimates, there are proven resources of Canadian ammolite that could last for around 20 years with their current speed of mining. “It is a finite resource. We could mine more each year but we do not want to do that. We will spend more effort in marketing ammolite in Asia, Australia and South Africa and we plan to double its price in the next five years,” said Maull.

Ammonite fossils

Apart from its ammolite and jewellery business, Korite also sells ammonite fossils, which constitutes about two percent of their production. According to the laws of Canada, if an intact ammonite fossil is found, it must be preserved as a whole piece. Similar to that of ammolite, ammonite fossils are graded according to its colours, brightness and shape though the price of each piece has to be determined individually.

On a special note, M C Wong reminded buyers that ammonite fossils are also produced outside Canada of much lower value. There were cases where a type of small Madagascan ammonite fossil with some effects of play-of-colour was sold as Canadian ammonite fossils. As there are huge differences in the price, supply and appearance between Canadian ammonite fossils and ammonite from other origins, consumers must stay alert.