Pearls are some of the most precious stones in the world. However, unlike many other stones, pearls are not formed from minerals, as are diamonds and other gemstones. Rather, they come to be in a life form – an oyster or a mussel. When a foreign object enters the shell, the creature releases a material as a defense mechanism. This material encases the foreign object and over time turns into what we know as a pearl. This process is very rare and hard to find, therefore, the natural procedure is mimicked by artificially triggering this process in both saltwater and freshwater mollusk. The results are cultured pearls.
Wild pearls refer to those found in nature, without any human intervention. These days, very few natural wild pearls are found. Saltwater and freshwater pearls look similar but they are different, both in terms of the waters their hosts lived in as well as the creatures that created them. Saltwater pearls are formed in ocean oysters whereas freshwater pearls are most often created in mussels found in lakes, rivers, and ponds. Freshwater pearls can come to be in warmer climates as well as colder ones, which is why they also originate from Scotland.
Since wild pearls are so hard to come by, the only real option in terms of creating the “real thing” is recreating the pearl-making process. This entails growing pearls in their natural habitat. Only the trigger is induced. The rest occurs on its own. Most of the world’s cultured freshwater pearls come from China. A small piece of mantle tissue is inserted into the mussel, much like a parasite finds its way naturally into a mussel or an oyster. This graft then produces a pearl sac, into which carbon calcium is inserted, creating a pearl. There are two main kinds of cultured pearls: beaded and non-beaded. Those grown with a bead are often grown in the gonad and not the mantle whereas beadless pearls are produced in the mantle. Beadless cultured pearls are also typically grown in freshwater shells and beaded pearls are often cultured in saltwater shells.
Only an x-ray can determine whether a pearl is cultured or not. Synthetic pearls on the other hand can easily be detected by rubbing two together. If they are fake, there will not be any friction. If they are wild or cultured, they will grind into each other and leave a mark.