Can an all-nacre, non-nucleated pearl from a cultivated salt-water oyster or freshwater mussel be called natural? Gemologists will answer this question with an emphatic “no.” When pressed for reasons, they will argue that any pearl taken from a nucleated mollusk, even one that grew by accident, must be classified as cultured.
But evidently the many Arab buyers who pay thousands of dollars for fine-quality, large-style specimen strands of these spontaneities think otherwise. If they represent interventions into nature, it is of a divine, not human, kind. “Arabs have never been comfortable with the idea of buying pearls that mollusks were forced to Grow,” says Mitsugu Nakanishi of Hikari South Pearl Co., Los Angeles. “But they have no qualms about buying pearls from the same animals when they are the result of chance.”
For years, these chance, or what renowned gemologist Robert Webster called “adventitious,” pearls were known as “seed” pearls because most were very tiny, usually under 2mm. But as the South Seas has become a major producer of chance pearls, many 10mm and more in width and 15mm or more in length, they have become known simply as “keshi.”
Because so much supply is taken up by the Islamic world, not many attempts have been made to popularize keshi pearls in this country. The handful of importers who stock them usually don’t even bother to make a domestic market for them. Rather, most view keshi as an exotic departure from the norm of cultured round pearls. But given their rarity, beauty and price, fine keshi deserve immediate elevation from curiosity to connoisseur status.
Repeat Performers
Unlike the oyster (pinctada martensii) used for saltwater pearl culturing in Japan, both the freshwater mussel (hyriopsis schlegeli) and saltwater oyster (Pinctada margaritifera), used for pearl culturing in Japan and the South Seas, respectively, live long enough to be used for up to three pearl-growing cycles. Many of these hardy mollusks that survive their first harvesting tend to grow pearls spontaneously if returned to the waters for a second growing cycle. They don’t even have to be re-nucleated to produce pearls. (Freshwater mussels are implanted with mantle tissue only while saltwater oysters are implanted with both mantle tissue and bead nuclei.)
According to pearl farmer John Latendresse, American Pearl Co., Camden, Tenn., keshi result when microscopic epithelial cells (that cover body surfaces) dislodge from implanted mantle tissue, find their way to suitable places in the mollusk’s anatomy and there grow renegade pearl sacs. In time, each of these becomes a fully formed pearl.
Ironically, pearl culturers try hard to minimize the possibility of keshi growing in their mollusks, even though they consider them natural and thus rarer than the cultured variety. “There’s only so much nacre that an animal produces,” Latendresse explains. “So the more keshi that grow, the more your cultured pearls are being deprived of nacre.”
No wonder then that keshi prevention is a paramount concern at many pearl farms such as those of master pearl grower Nick Paspaley in Australia. Latendresse says Paspaley has slashed the occurrence of keshi to infinitesimal amounts. “On the other hand,” Latendresse adds, “less experienced farms in Tahiti and the Cook Islands (known for black pearls) are producing large numbers of keshi.
That’s why you’re seeing so many dark-gray keshi lately.” The question remains: Should these byproducts of pearl culturing be considered cultured pearls? According to one U.S. government official versed in gemology, they should not be called “cultured” because they are produced spontaneously. While this opinion may offend some gemological purists, it will not doubt sit well with keshi lovers like the Arabs who feel that “cultured” is a synonym for “unnatural” when used with pearls.
To the Japanese pearl growers who coined the term, “keshi” has always had more to do with the size of the pearls than how they grew. Interestingly, the word means “tiny particle,” and until recently it referred to seed or “poppy” pearls, of which it is still common to see 20 or more strands combined into what are called “twists.” For most connoisseurs, however, keshi refers to big sizes and is generally thought of as a variety of South Sea, not Japanese, pearls.
A very affordable variety.
Creams of the Crop
Whether from mussels or oysters, keshi pearls are invariably baroque in form. The fact that the vast majority are fancy-shaped is perhaps the greatest single factor in their low price—or at least low in comparison with comparable quality round pearls. Our price survey for this profile shows fine quality keshi strands composed of pearls that are at least 10mm in width selling in America for anywhere from $6,000 to $20,000. According to New York-based South Sea pearl specialist Albert Asher, a strand of high luster keshis costs one-tenth as much as a comparable strand of rounds. Latendresse points out that fine keshi pearls are a particularly good bargain in this country, where they cost less than half of what they do abroad.
What Americans fail to appreciate about top-of-the-crop South Sea keshi pearls is their rarity and magnificence. These are pearls with luster so intense it is, as Asher says, “almost blinding.”
Besides strong luster, fine keshi pearls boast impressive amounts of orient, a trade term for pearl-surface iridescence caused by the refraction of light between successive nacre layerings. Although this trait is usually noticeable in better baroque pearls, it is heightened in fine keshi because they are completely composed of nacre. Thus fine keshi combine reflected and refracted light—luster and orient respectively—to a degree rarely found in cultured pearls.
As with other South Sea pearls, keshi come in a wide range of colors that have much to do with their origins. Most we have seen are bluish-white and silver-gray indicative of Australia and black indicative of both Tahiti and the Cook Islands. However, there are cream-whites and yellows that suggest Indonesian and Philippine farms. In addition, there are fancy colors such as gold and mauve.
The growing number of South Seas pearl farms might tempt one to predict that fine keshi will become more abundant in the years ahead. But just the opposite is likely to happen as farms get the knack of keshi control. This prospect of increased scarcity only makes present fine keshi prices seem all the more attractive.
Please note: this profile was originally published in 1992 in Modern Jeweler’s ‘Gem Profiles/2: The Second 60’, written by David Federman with photographs by Tino Hammid.
The keshi pearl strands shown in the header image are courtesy of Adachi American Corp., Los Angeles. The loose pearls are from Hikari Southsea Pearl Co. Inc., Los Angeles.
