The Issue of Tissue

Marc Freeman says his round metallic-luster 10 mm and 11 mm Chinese freshwater cultured pearls are 100 percent nacre. There’s no nucleus. And he challenges the gem-identification laboratories that call Chinese cultured freshwaters “tissue nucleated” but describe Japanese and Chinese akoya saltwater bead-nucleated pearls—with less than 10 percent nacre—as “cultured.”

Freeman, owner of Freeman Gem Co. in Los Angeles, has spent a lot of money, time, and effort providing proof that his pearls are top quality—all nacre (no nucleus), natural color (not dyed or bleached), and naturally round (not bead-nucleated or ground round). Since he doesn’t accept current nucleation terminology, he’s providing new vocabulary for the product. But will anyone use it?

According to Freeman, Chinese freshwater cultured pearls are “activated” by a minute piece of mantle tissue. Producers don’t use a mother-of-pearl bead or a Chinese-freshwater-pearl bead to generate growth. Freeman doesn’t like to use the term “tissue nucleated,” since the tissue used to create the pearl is no longer in the nucleus. “It’s as important to talk about nucleation as it is to talk about color and luster,” says Freeman. “The gelatinous tissue, 1 mm × 1 mm × 0.5 mm, dissolves in the process of activation, leaving no trace after the formation of the pearl.” With no tissue, the pearls are 100 percent nacre, or, as he calls them, PurePearl.

The labs agree, yet tradition still stands. “Tissue grafts are used to instigate the growth of the cultured pearl,” says Ken Scarratt, pearl expert and director of the Gemological Institute of America’s new Bangkok, Thailand, research lab. “If one were to section many of this type of cultured pearl, there may or may not be evidence of the tissue present. Based on examining many thousands of these structures through radiographs over the years, it appears in many instances the actual tissue graft ‘decays,’ leaving a void or some matter in the area of nucleation.”

Freeman also calls his pearls Round by Nature, to distinguish them from akoyas, South Seas, and Tahitians, which acquire roundness from a large, spherical mother-of-pearl bead. To produce a 7 to 8 mm akoya, for example, requires a 6 or 7 mm bead, which remains inside the shell for two to three years and results in nacre thickness of 0.5 mm. Freeman’s Round by Nature pearls grow inside the shell for three to 10 years, with no spherical bead and no guarantee of roundness.

What the Labs Say and Do. The GIA Gem Lab conclusion for a typical bead-nucleated cultured pearl is: Cultured Pearl, Weight ___ Cts. The conclusion for a freshwater tissue-nucleated cultured pearl is: Freshwater Tissue-Nucleated Cultured Pearl, Weight: ___ Cts.

“The distinction between freshwater and saltwater origins has always been made with natural pearls,” notes Scarratt. “Pearl dealers considered freshwater pearls under a different commercial category to saltwater or ‘Oriental’ pearls, and therefore they needed us [the laboratories] to distinguish between the two. This historic convention seems to have been carried over to cultured pearls; indeed when tissue-nucleated CPs became available, cultured-pearl traders asked that we indicate whenever tissue nucleation was involved—as ipso facto the description ‘cultured pearl’ indicated to them bead nucleation.

“To our knowledge, most lab- oratories do distinguish tissue-nucleated cultured pearls on their reports; however, it is not inaccurate to describe them as ‘cultured’ alone. In most instances, the nacre is thicker in tissue-nucleated cultured pearls than bead-nucleated cultured pearls; however, the nature of the nacre is different in each product, so it is not just thickness that causes the beauty in pearls and cultured pearls,” he adds.

Pearl X-ray reports from European Gem Lab read “cultured saltwater pearl” or “cultured freshwater pearl.” There is no mention of nucleation.

Pearl-identification reports from the AGTA Gem Testing Center note bead or nonbead nucleation. For the typical bead-nucleated cultured pearl, GTC notes: Identification: Cultured Pearl; Variety: Nacreous [as opposed to non-nacreouslike, e.g., conch pearls]; Comments: Cultured white saltwater pearl with bead. For Chinese freshwaters, GTC plans to revise its conclusion to read something like the following: Identification: Cultured Pearl; Variety: Nacreous; Comments: Cultured white [or other color] beadless freshwater pearl.

Dr. Lore Kiefert, GTC’s new laboratory director, notes that upcoming changes are likely. “As we go further into the future, there will be cases where the beads are not shell beads anymore. We may have to identify these as well, and write ‘freshwater shell bead,’ ‘saltwater shell bead,’ ‘dolomite bead,’ etc.… I hope it doesn’t get to that.”

For more information about PurePearl, contact Marc Freeman in Los Angeles at (800) 321-4367.