By Robin Skibicki
Not all gemstones are minerals with a crystalline structure. In fact, some were formed through biological processes of living organisms, such as plants and animals. These natural beauties are referred to as organic gemstones and include several varieties that are important to the gem trade. We’re talking about pearls, coral, amber, ammolite, and shell, just to name a few.
Pearls are pretty much perfect for any occasion. It doesn’t matter if you’re dressed in silks and satins or khakis and jeans, they go with everything! There are several types to choose from, like freshwater or saltwater, natural or cultured, with such varieties as Akoya, Keshi, South Sea, and Tahitian.
There are hundreds of species of coral throughout the world, but only a few are used for fine jewelry. Corallium japonicum and Corallium rubrum are two varieties of red coral commonly used to produce jewelry, and Antipatharia, a species of black coral prized for its lustrous, black appearance after polishing.
Amber had its moment in the spotlight when it appeared as a source for “Dino DNA” in the movie, Jurassic Park. This fossilized resin of ancient tree sap dates back 25 to 50 million years, with some of the oldest known material dating back 290 to 350 million years ago. Amber comes in over 300 different shades, with the most common colors being honey, green, cherry, cognac, citrine, and butterscotch.
Ammolite is an iridescent gemstone material that comes from the fossilized shell of extinct squid-like creatures called ammonites. They only come from one place: Alberta, Canada. Although they have been forming for millions of years, ammolite first appeared in jewelry in the 1960s and was recognized in 1981 as an organic gemstone.
Shell has been used for decorative purposes for centuries and was most likely the by-product of the search for food. It’s been used for everything from buttons to knife handles, from cameos to necklaces. In jewelry design, the two most familiar types of shell are abalone and mother-of-pearl.
Interesting facts: Abalone is composed of mother-of-pearl. Mother-of-pearl is called nacre, which makes the outer layer of pearls.
Visit an AGS-credentialed jeweler near you and ask them to show you some organic gemstones!