Ammolite and ammonite You know all about amber and pearls, the best-known gemstones created from living organisms. Ammolite is the third organic gem and the hardest to find.

It is found primarily along the eastern slopes of the Rocky Mountains of the United States and Canada. It is made of the fossilized shells of ammonites, which are prehistoric squid-like creatures that were once a favorite snack of dinosaurs, sharks and turtles.

Among the first to collect ammonite fossils were the Blackfoot Indians, who called it iniskim, or buffalo stone, and believed it to bring good luck.

The use of ammolite in creating breathtaking jewelry is a recent phenomenon. In 1981, ammolite was officially designated a gemstone by the World Jewellery Confederation.

Jewelry-quality ammolite may be a very thin layer, less than 1 mm, and not often mined without its accompanying layer of chalk or shale matrix.

Ammolite is usually worked into cabochon shapes and mounted in gold, with diamonds as accents. Because it is fragile, ammolite is best reserved for use in pendants, earrings, and brooches; if used as a ring stone, ammolite should be given a hard protective cap, namely one of synthetic spinel as used in triplets. Small whole polished ammonites were historically mounted in gold, silver or jet as brooches starting around 1850. Use mild soap and warm water to clean ammolite jewelry and avoid ultrasonic cleaners.