As we approached the pearl farm, the singing family greeted our covered boat. They divided us into two groups of about 10 each to listen to the presentation on pearl-making. The patriarch of the family gave the presentation to one group, and one of his daughters spoke to our group.
After listening to the presentation, I can see why the black pearl, poe rava, can be so expensive. The oyster that grows the pearls, Pinctada margaritifera, is extremely abundant in Polynesian waters. The shells of the oyster have been used since ancient times to make jewelry, fish hooks, and lures. In addition, the European button industry used a large amount of the shells prior to the invention of cheaper means to make buttons. Black pearl cultivation now takes place on about 30 islands in the South Pacific, and has largely replace copra (coconut meat) and fishing as a source of revenue.
The pearls produced by the Pinctada margaritifera vary in color from pearly white to nearly black and include purple, gray, champagne, and greenish colors. There are no pearls that are completely black in color like an onyx.
Making pearls is an arduous process, and not just for the oysters! Either divers collect three- to five-year-old oysters to be used for the pearl cultivation, or they are raised by the pearl farmer. The farm we visited "grew" their own oysters. At certain times of the year, the oysters release sexual substances that are fertilized in the water. These young oysters, known as seed oysters, swim around for a few weeks before attaching themselves to coral. The pearl farmer catches these seed oysters and attaches them to underwater rearing lines like those at the right. Unfortunately, like most farm crops, you can't then just sit back and watch the oysters grow. The farm family must remove the oysters from the water about every three months and wash them with a spray hose to remove any algae that has grown on the shells and prevent the algae from killing the oysters. At this farm, they were cleaning oysters continually, since it took about three months to go through the entire crop!
When the oysters are three to five years old, they are ready for cultivation. First, the farmer sacrifices a donor oyster and divides its mantle into about 50 small particles called grafts. The recipient oyster is pulled from the water, fixed to a support and held open with forceps. (see the oyster in the support in the picture at the left) The grafter, usually a Japanese expert, uses a scalpel to cut the back of the productive organ (gonad) of the oyster and insert the graft from the donor oyster. The grafter then inserts a 6 mm perfectly spherical bead, called a nucleus, into the gonad so that it is in contact with the graft.
The grafted oysters are placed in small bags linked together to form "keep nets" (to protect them from predators) and lowered back into the lagoon, where they are regularly cleaned and inspected. (The small bags will also enable the farmer to see and retain any nuclei that have been expelled by the oysters.) If the procedure is successful, the graft cells develop around the nucleus to form the pearl sack. My mom is standing next to a pearl sack in the picture at the right. The graft acts as an irritant, and the sack secretes the nacre (mother-of-pearl) material which forms the layers of the pearl. It normally takes from about 18 months for a 1.5 mm layer of mother-of-pearl to surround the nucleus. Sometimes the grafter implants a second nucleus to grow a larger pearl of about 15 to 20 mm. The process for the larger pearls takes about three years.
Growing black pearls is continued on page 2.
