Ammolite

Ammolite is fossilized ammonite, a coiled shellfish related to modern-day squids that existed some 65 to 410 million years ago. The name “ammonite” comes from the ancient Egyptian god Ammon, who is represented by the head of a ram with twisted spiral horns, reminiscent of ammonite’s curled-up shells. Ammonites are found worldwide, but in the southern portion of Canada’s Alberta province, the ammonite shell displays vibrant colors. Canadian ammonites can be found as large as 90 cm in diameter and typically show red or green iridescence. Because fossil ammonites are protected by the Alberta Historical Resources Act, scientific or display-quality specimens may be retained by the Crown.

History and romance. According to legend, a Native American woman of the Blackfoot nation was the first to discover the colorful fossil in the foothills of the Canadian Rockies. It was found during a harsh winter when the buffalo had not returned and the tribe was starving. The story goes that the beautiful gem told her that it was powerful medicine, and if she took it back to the tribe, it would provide food for her people. She did, and the next morning a large herd of buffalo appeared. From then on, the Blackfoot used ammolite in bison-hunting ceremonies, wrapping them in medicine bags made of buffalo hide. As the bison disappeared, ammolites were used for healing, but still referred to as “the buffalo stone.” The Blackfoot believe that those who carry the ammolite are bound for wealth and abundance.

Ammolite was rediscovered in 1908 when a member of the National Geological Survey team found ammonite fossils along the St. Mary’s River in Alberta. But it was not until 1981 that enough high-quality ammonite was uncovered to make commercial mining feasible.

Color variations. Ammolite can be found in a rainbow of colors but commonly occurs as red, gold, or green. Blues and purples are rare and highly prized. Showing a minimum of two colors (although three or more colors are preferred), top-quality ammolite is considered to rival fine-quality black opal. And like opal, the colors are directional, shifting from one color to another as you rock the gem back and forth.

Qualities. Intensity or brilliance of colors, color ranges, and the pattern of coloration are the three important factors when judging quality. Obviously, the more intense or bright the colors, the higher the quality. Ammolite is considered top-quality when it has three or more colors. Finally, the areas between colors—the dark separations—are considered either as creating specific patterns or as a flaw. A gem with a very distinct and appealing pattern (such as floral, stained glass, or ribbon patterns) can be classified as top quality, as can one with few or no separations at all.

Pricing. Because of each stone’s individuality, it is difficult to state specific values. Ammolites are priced per square millimeter according to the quality of each individual stone. Triplets range from $100 to $1,000 per stone, with natural gems priced at $250-$2,500.

Care and cleaning. Since ammolite is approximately 4.5 in hardness, due care is required. Customers should avoid wearing ammolite jewelry when in contact with acids, ammonia, hairsprays, and perfumes. Cleaning can be accomplished with a soft brush using mild soap and water or pearl cleaner.

Bench settings and precautions. Prong settings should be avoided for the soft, natural gems. However, because of the hard synthetic spinel top, triplets can be prong set. Bezel-setting, on the other hand, has just the opposite recommendation: For natural gems, a bezel is appropriate, but triplets could become separated when mounting in a bezel setting. Since glues are sometimes used to set triplets into bezel-like settings, the bench jeweler should be aware of the difficulty in unmounting the gem before sizing or repair.

Recommended reading. For more information, see the following references:

Donna Barnson, Ammolite, Selkirk, Manitoba, 1998.

Dr. Fred Pough, “Ammolite, Grandmother of Pearl,” Lapidary Journal, January 1986.

Special thanks to Korite International, Calgary, Alberta, Canada, and A+A Jewelers, Toronto, Ontario, Canada, both manufacturers of ammolite gems and jewelry.