Ammolite is a trade name given to a thin iridescent aragonite shell material that is found on two species of extinct ammonite fossils. Other less-frequently used trade names for Ammolite are "Calcenite" and "Korite."
Ammonites were squid-like creatures with sharp, beak-like jaws, a spiral shell and tentacles. They went extinct about 66 million years ago.
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.
Ammolite is a rare material. All of the world's commercial production comes from a small area along the St. Mary River in southwestern Alberta, Canada. There, two companies mine Ammolite from thin layers in the Bearpaw Formation where the ammonite fossils are found.
The International Gem Society estimates that only about 5% of the ammonites found in Alberta have suitable gem material on the shell surface. Of that amount, only about 20% of the shell can be used. Fossilized ammonite shell is comprised primarily of aragonite (the major constituent mineral of pearl) with trace elements of aluminum, barium, chromium, copper, iron, magnesium, manganese, silicon, strontium, titanium, and vanadium. The iridescent outer layers may be 0.5 – 8 mm thick before polishing and 0.1 – 3 mm thick after polishing.
Ammolite is fairly new to the gem and jewelry world. Despite their historic formation, Ammolite is one of the few new natural gems (with Tanzanite and sugilite) 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)
Gem-quality Ammolite produces a spectacular display of iridescent color when it is observed in reflected light.
The colors of an individual stone can run the full range of the visible spectrum or be limited to just one or two colors. A higher grade Ammolite gem will have either a very strong, bright single color or a range of bright colors. These gems can show any color of the rainbow. Lower grade gemstones will show less vibrant colors in a more limited range. Generally, red and green are more common than blue or purple. Certain hues, like crimson, violet, and gold, are very rare and in high demand.
Very often, Ammolite is used to produce triplets. These are made by backing the fragile iridescent material with a thin slab for stability and topping it with a transparent cover for protection.
Clear quartz or spinel can be used for the transparent cover. Black shale or another material can be used for the backing. Some Ammolite is made into doublets, which only requires adding a backing or transparent cover as needed. Many stones are impregnated with epoxy for stability.
The highest quality rough is usually cut into free-form shapes to produce gems of maximum carat weight. These are used in designer jewelry. Other grades of material are cut to standard shapes for use in commercial jewelry.
When assembled stones include a clear cap, it normally has a minimum amount of doming to provide the best view of the Ammolite below. A small number of stones have a faceted cap for customers who like that appearance.
Ammolite was known as "Iniskim" ("buffalo stone"), by the Native societies. It was, and is, honored as a powerful talisman and has its own Traditional Legend.
In the late 1990s, practitioners of feng shui began to promote Ammolite as an "influential" stone with what they believe is the power to enhance well-being and detoxify the body.] Named the "Seven Color Prosperity Stone", each color is believed by feng shui practitioners to influence the wearer in different and positive ways.
Ammolite is known to be helpful during childbirth for both the mother and the baby. It can also enhance physical vitality and stamina, as well as stabilize the pulse and the blood pressure. This stone's healing energies can also regulate the metabolism and lift depression.