Califonia Bountiful

Pearls of wisdom

Jan./Feb. 2007 California Country magazine

La Jolla entrepreneur shares secrets of culturing pearls.

La Jolla entrepreneur shares secrets of culturing

Paul Cross holds up a bead made of shell from an American freshwater mussel, the basic nucleus of saltwater cultured pearls.

From the depths of the ocean to the showcases of Tiffany's, pearls have long been treasured for their intrinsic beauty and mystique.

The alluring jewels adorned the heads of royalty and draped the necks of the rich and famous. Fashion designers still regard the classic beads as a foundation of every woman's wardrobe, an accessory that will always be in vogue.

Until the turn of the 20th century, the little gem was an accident of nature, so rare a find that deep-sea divers had to open thousands of shells to get at the prize. With the advent of pearl culturing, the precious jewels are now more accessible for the common man. But for nearly a hundred years, the techniques for coaxing pearls from mollusks have been the well-guarded secrets of the Japanese, who still dominate the pearl industry today.

Paul Cross would like to change all that. Since the mid-1980s, the jeweler-turned-entrepreneur has been on a mission to uncover the industry's secrets and take the mystery out of pearl culturing. After establishing the only freshwater pearl mussel farm in the state, primarily as a research project, he formed American Bio-Gem Inc., which specializes in pearl culturing technologies. Located in the resort town of La Jolla in San Diego County, the company's current focus is teaching other pearl farms and aquaculture operations the secrets of culturing pearls.

"We want to share it because we want to encourage the people who grow," Cross said. "We don't want to be growers. But we want to be able to give the growers something to work with."

Paul Cross fishes out an abalone, which he will use to culture a mabé pearl. He keeps a variety of abalone and turban snails in a tank at his research facility in La Jolla.

The U.S. pearl culturing industry is still relatively small and obscure, but Cross said opportunities are ripe for California aquaculture farmers, who are already growing marine life for food. His intention is to produce less expensive, quality pearls that are more accessible for the everyday consumer. With the help of aquaculture farmers, California could become the next epicenter of the pearl industry.

While most people associate pearls with oysters, a variety of mollusks have been used to produce pearls. Cross said much of his work is still with oysters, but he has also been experimenting with abalone and turban snails found along the California coast.

Turban snails are an abundant resource and currently have very limited commercial and practical use. Abalone is a different story. The state's abalone population has dwindled in recent years due to pollution, overfishing and other problems. Now a handful of California aquaculture farms are growing abalone. Cross said if growers want to add value to what they're already growing, grow a pearl with it.

"It's basically piggybacking on a process that already exists because the farmers are already growing these things for the meat," said Michael Crowe, who handles international business development for American Bio-Gem. "We think by doing this, it'll bring a greater awareness of these marine resources and how they come to be used."

Essentially, natural pearls are formed for the same reason that cultured pearls are formed: A foreign object--usually a parasitic organism, in the case of natural pearls--gets lodged inside the mollusk. Contrary to popular belief, it is never a grain of sand, said Cross. To protect itself from the intruder, the animal coats the irritant with layers of nacre, also known as mother-of-pearl, the same substance it uses for shell building.

"Before we knew how to culture them, the animals did in fact produce pearls naturally," said Crowe. "But they did so rarely. So the way early pearl divers got around that is by killing millions of them. They would take many thousands of oysters out of the water just to find one pearl. But very rarely are natural pearls perfectly round."

The traditional round pearls that most people think of are usually cultured from saltwater pearl oysters--different from edible oysters, which do not produce the same pearly nacre. To induce the oyster to make a pearl on command, a skilled technician inserts a tiny round bead--typically made of shell taken from an American freshwater mussel--and a piece of mantle tissue from another oyster inside the host oyster's gonad. This causes a pearl sack to form around the irritant bead. The sack begins to secrete nacre, coating the bead. After a period of time, a pearl is ready to be harvested.

Depending on the type of species and the technique used, pearls can vary in color, size and shape. For example, Tahitian black pearls are produced by the black-lipped oyster and are naturally black. Abalone also produce pearls with a unique color. Since the animal has a different anatomy from oysters, the pearls are usually grown against the interior of the shell. This procedure produces a half-sphere pearl, or what the industry calls a "mabé" pearl.

Cross said abalone and turban snails are both ideal to use to make mabé pearls, which are relatively easy to grow. In his research facility in La Jolla, it took him literally a few minutes to do an implant with an abalone.

The abalone is mostly muscle and quite strong, so to get under its shell, Cross first anesthetizes the creature by using CO2. He then rolls back the abalone's flesh to find the spot where he wants to put the implant and drills a hole there. The process is similar to ear piercing. The implant--which can be made of rubber or metal--is held in place like an earring with a post and a backing.

The abalone then goes back into the water for about three months, a much shorter growing time than oyster pearls, which can take 18 months to several years to grow. Cross said young abalone grows nacre at a much faster rate. When enough nacre has covered the implant, the pearl is cut out with a high-frequency diamond drill.

From a jeweler's point of view, mabé pearls are considered less valuable than full round pearls because they can't be strung into necklaces and must be set into rings, pendants or earrings.

Arthur Seavey, co-owner of Monterey Abalone Co., located in the city by that name, said his aquaculture operation tried growing mabé pearls in the 1990s. After about five years, however, he gave up because of the high mortality rate of the abalone and the low percentage of marketable pearls they produced. The consumer's attitude toward mabé pearls didn't help his fledgling venture either.

"I remember people saying, ?Oh, that's not a pearl. What is that?' It's a mabé pearl," Seavey said. "Well, they've never heard of it. It's not a pearl because it's not round."

At least one California aquaculture farm, US Abalone in Davenport, Santa Cruz County, is currently culturing mabé pearls from abalone.

Cross said mabé pearls have a different versatility in that he can easily grow virtually any shape he wants by using different implant designs--from popular iconic images of Mickey Mouse, Elvis Presley and the Nike swoosh to panda bears, nautical symbols and the Rolling Stones.

But would consumers buy a Mickey Mouse pearl? Wouldn't such a product cheapen the very mystique and status appeal of the treasured gem?

"What people are buying here isn't a pearl first. It's a brand or an icon or logo first," Crowe said. "It isn't the pearl per se, it's the logo realized in pearls. We've always had the logo. We've always had the image. But what if we can make that in pearl? That would be cool."

Another important selling point is that the pearls will be affordable--from $35 to $175 at the retail level. And each pearl will be real and unique, not only by virtue of the design but also by the very nature of how the animal created them.

"We can take any design concept and build all these separate shapes, culture them, get them into Tiffany's and they can build exquisite pieces around them," Cross said.

Pearl culturing also gives aquaculture farmers an additional economic incentive to replenish the world's diminishing marine population, he said.

"That's what's happened in the Sea of Cortez," said Cross. "Because of the project down there for cultured pearls, the baby oysters that they've grown are now in the natural system, where before, they were wiped out.

"Aquaculture is needed. The way to keep this stuff going on the planet is to encourage it through animal husbandry."

Ching Lee is a reporter for the California Farm Bureau Federation. She may be reached at 800-698-FARM or

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