Cultured Pearls: Pearls With a Bit of Culture
Just about any pearl you’ll find today- in a store, at a jeweler, or virtually anywhere else- is a cultured pearl. Cultured pearls are an effort made by pearl farmers in order to maintain the delicate balance of nature, while still responding to the demand for pearls in the jewelry marketplace. Culturing pearls began at the very beginning of the 20th century, when several inventors discovered the techniques required in order to cultivate pearls. The most famous of these inventors is a man named Kokichi Mikimoto, known today around the world as the father of Akoya pearl.
To being the pearl cultivation process, the pearl technicians introduce a foreign object such as a piece of tissue or a mother-of-pearl bead nucleus into a tiny incision made in the gonad of the host mollusk; this process is known as "grafting", basically nucleating the oyster or mussel, stimulating it to pearl formation. The automatic reaction of the mollusk is to grow a pearl sac around the irritant and begin coating it with layer of nacre to smooth it over.
Pearl farmers can create cultured pearls in either saltwater or freshwater, and in different types of mollusks.
- Cultured Saltwater Pearls – These pearls are cultivated in saltwater oysters found oceans and tropical atolls or lagoons. Saltwater pearl types include the small, white Akoya- typically farmed in Japan and China- black Tahitian pearls from French Polynesia and White or Golden South Sea pearls from Australia and the Philippeans. A perfectly round shell-bead nucleus, along with a tiny 1mm slice of donor mantle tissue from another oyster is inserted into the oyster's gonad; this is the "base" or template for the oyster to begin forming a pearl sac around and eventually begins layering crystalline nacre in concentric layers, much like an onion. Saltwater pearls can be harvested as early as 18 months, but the longer the pearls are left in the oyster to acquire thicker layers of nacre, the better the resulting quality of the pearls will be at harvest. For example, South Sea pearls, and Tahitian pearls will usually take between 2 and 3 years to form. Akoya pearls from Japan will usually take less time, at under 2 years. This means that a large, fine Tahitian or South Sea pearl necklace can take many years to properly match for size, luster and color, raising the price exponentially higher. The countries that are best known for producing cultured saltwater pearls are: Japan, China, Vietnam, Indonesia, Burma, Thailand, the Philippines, Australia, and French Polynesia.
- Cultured Freshwater Pearls – Chinese freshwater pearls are farmed in freshwater lakes, rivers and man-made ponds, and are grown within freshwater mussels- typically Hyriopsis cumingii or Hyriopsis schlegeli or a hybrid thereof. Freshwater pearls are begun by inserting tiny pieces of donor mantle tissue into the mussle; as many as twenty-five insertions may be made per valve, or each side of the shell. As you can imagine, Freshwater pearl harvests produce substantially more pearls than that of their saltwater cousins! The mussel begins forming pearl sacs for each irritant, and after a period of about two years the pearls are harvested. Each mussel can produce a wide variety of natural colors ranging from lavender to pink and peach, bright silver white to deeper creamy/ivory shades. Freshwater pearliculture technology is constantly changing, and new, exciting and unique varieties of pearls make their debuts at the gem shows yearly. The sky is the limit with cultured Freshwater pearls!
Among the many advantages of cultured pearls over natural pearls is that is is becoming easier with every passing year to produce a specific pearl shape, color and size on demand, and culturing technologies are improving all the time. Culturing pearls also means that wild oyster populations, once over-fished to near extinction around the world have been given a long-deserved rest from pearl hunters and are once again allowed to flourish and regain their once plentiful numbers.
Clean, balanced environmental conditions are essential to the health of the mollusks and the resulting beauty of the pearls, which means that pearliculture is one of the most environmentally friendly gem types in the world. While other gems and precious metals generally mean strip mines, soil leaching and forest deplacement, pearl farming is a cooperative experience between man and nature, an ever evolving balance and a never ending search for beauty.