In-Body Bead-Nucleated (IBN) Freshwater Pearls

Ripple pearls = China freshwater IBN (In-body bead nucleated) pearls

The most important accomplishment in China's pearl cultivation history reached a wider audience ca. 2010. At first the product had no widely known name, sharing "bead nucleated" with flame pearls, in spite of the very different operating skills required and the different look of the product. (See here for details.)

Baroque pearls  resulting from this cultivation method usually have surface texture causing them to be popularly known as ripple pearls. Now comprehension of this product is impeded by a surfeit of names, competing with each other in an industry obsessed with branding. "Proper" names, among them trademarks, say nothing about the product except who sells it. With pearls, proper names, eg Mallorca, have tended to imply imitations. The protagonists of names like "Ming", or "Edison" pearls are unlikely to succeed in making the whole world use their brand, downstream use of which merely implies a user knows no descriptive name, or perhaps is beholden to a certain supplier.

In 2023, a GIA employee invited to lecture on pearls at "Pearls by the Bay" (hosted by Kojima Pearls in northern California), was heard not only to use to "Edison" brand to describe Chinese IBN pearls, but also to state that trademark"s owner, Zhang Wei Jan, invented these pearls.  I of course pointed out both inaccuracies.  In stark contrast, the late Robert Crowningshield, also of GIA, wrote in 1962 "Another suggestion has been that, since Lake Biwa, so far, is the only culturing center for these pearls, the term "Biwa cultured pearls" be used. This suggestion is not valid for the Gem Trade Laboratories, since we do not attempt to give sources of other gem materials."  I have long recommended his article "Fresh Water Pearls" to students of pearls.  Excerpts can be read here. 

In-body (bead) nucleation is not a phrase that rolls easily off the tongue. At the turn of the century,  very few people were knowledgeable enough about pearl production to comprehend it.  But that is changing rapidly, with knowledge of pearls spreading even as we become aware of more products with different characteristics and requirements.

Baroque in-body nucleated ripple pearls tend to have a surface texture not seen in flame type bead-nuc pearls. It should come as no surprise that these pearls have many similarities to Japan Kasumi pearls, as those are all made by in-body nucleation. Many have deep colors and/or strong goldy highlights. Semi-baroque strands without major irregularities sometimes exhibit extremely strong luster and colors.

Some people will invariably use a name associated with a certain "look".  The expression China Kasumi may serve to disambiguate, but is resented by our Japan Kasumi pearl suppliers, and not a proper use what is, after all, an abbreviated place name.  We prefer In-body bead nucleated  (IBN) as the most succinct and unequivocal naming for this product.

This "new" cultivation method has been done on a relatively small scale in China, probably since at least 1990. We were surprised by the beauty and size (13-16mm) of the pearls of this type that we have been able to acquire since late 2007, exceeding the norm for Lake Biwa and Kasumi-ga-Ura pearls produced at least since 1980. Both size and nacre thickness suggest that these pearls have been cultivated for decades,  rather than just for a few years.

Beginning in 2010, IBN pearls  became widely available in more common sizes in the range of 9 to 12mm. In less than 2 years all our China pearl suppliers offered them in quantity, and as of mid-2013 they seem more common than (mantle nucleated) flame pearls with round nuclei. Still there is not any uniform nomenclature in use to differentiate among products. The most time-honored naming for in-body (bead) nucleated (IBN) in our experience is "iketchoo", at truncation of the Japanese name for Hieryopsis schegeli mussels. The implication is that the mussels are pure-bred, in contrast to other freshwater pearls which are from hybrids viable in environments where ikechogai are not.  Regardless of the truth of this claim, I consider it disinformation to imply that the difference is due to species rather than pearling technique. To test our belief that they are in-body, we persuaded a dentist to make some x-rays. The films show two drill holes in every nucleus - the one from implantation and the one from assembly to strand. Please see below for an explanation of the use of pre-drilled nuclei in freshwater pearl cultivation.

At this 2024 writing, I now have confirmation that Chinese IBN producers now nucleate not with shell, but a material reconstituted of ground shell and artificial binders. Simultaneous was the realization that the plastic nuclei did not have drill holes.

At this 2024 writing, I now have confirmation that many Chinese IBN producers now nucleate not with shell beads, but a material reconstituted of ground shell and artificial binders. In February, I bisected as 15mm China IBN pearl to find it consisted roughly half of nacre and half of a spherical plastic nucleus that did not have drill holes.

That means they have somehow solved the problem of separation of nucleus and active mantle tissue graft; due to greater muscular activity of mussels compared to Akoya oysters this is mainly a freshwater issue. Previously this was overcome by pre- drilling shell nuclei, inserting a tool like a slim ice pick, and spearing the active mantle tissue graft on the tip protruding from the nucleus. The action of withdrawing the tool after placement serves to attach the graft to the nucleus securely, in most cases.

How it is done is not known to your writer at present; perhaps a chemical affinity bonds graft to nucleus.

Mussels deposit nacre far more rapidly that akoya, so nacre thickness has been less of an issue. Depending on placement in the body (the gonad, being the most expendable organ for individual survival, is often mentioned, but even the harvesting cannot be done publicly lest cultivating technology be revealed) smooth round pearls with as much as 3mm of nacre can be made.

Attempting to resupply a customer's need I recently bought some 6mm IBN, a bit more semi-round than the semi-baroques I had been selling for half what I had to pay now, cash, in Hong Kong.

Known in the wide expanse of the internet as Freshwater Akoya, or the even wronger Chinese Akoya, Cfw IBN get ever closer to perfect shape in a wider range of sizes. The determined attempt to annex the Akoya market requires it.

I quipped to the customer, who expressed surprise when I wrote baroque shape is often a sign of thick nacre coating, that it won't be long till the makers of China IBN figure out that thin coating improves what passes as "quality". I hereby retract what I now see as an insult. Chinese IBN producers, a steadily growing branch, have certainly been aware about the inverse relationship to nacre thickness, ie growing time, and the ball bearing shape which is still the unnatural ideal. With artificial nuclei, the most easy way to detect thin nacre coating is not possible.

Mother-of-pearl nuclei, traditionally freshwater mussel shells cubed and ground round between rotating metal plates, exhibit clear lines between annual growth layers, and at a right angle, a nacreous reflection of the shell. Thus by rotating a pearl, thin nacre coating is easily detected due to the mono-directional luster of the nucleus. Viewed at 90 degrees, the nucleus layers are slightly translucent, similar to light seen through chick blinds of straw or bamboo. The Japanese word sudare『簾』, meaning chick blind, in a pearl context, denotes nacre coating inadequate to hiding these signs. Artificial nuclei have neither, making the determination of (the lack of) nacre thickness much more difficult.

Hitherto we observed that China produced pearls without than with nucleus. This no longer holds; especially round pearls whose sizes exceed 10mm diameter are likely to be in-body bead nucleated. The roundest pearls of this type we offer mostly have dimples and other minor imperfections, but the quality/price ratio improves by leaps and bounds. These are clearly products of a maturing industry destined to dominate the market of large and medium size IBN pearls as well.

Semi-round to near-round in-body-nucleated pearls

In-body bead-nucleation - details

In-body bead nucleated freshwater pearls differ significantly from flame type bead-nucleated China fw pearls, which became available around 2000.  Flame pearls are cultivated by inserting beads into pearl sacs that have been previously grafted in the mussel's mantle, after harvesting a non-nucleated pearl that grew there. Flame pearls tend to have fluid shapes and smooth surface, while in-body pearls show better conformance

Beginning around 2015,  China adapted ther now common IBN technology to producing 5-10mm sizes in freshwater mussels.  In addition to saving money by using composite shell nuclei in place of the traditional machine ground ones of pure (freshwater) shell.

Lake Biwa and Kasumi-ga-Ura areas in Japan produced in-body bead-nucleated fw pearls between the 1960's and the 1980's, and on an infinitesimal scale to the present day. Many operators made jobless by the 1980's environmental debacle in Japan are believed to have taken their in-body nucleation skills to China. Why did the fruits of that technology transfer, probably initiated over 30 years before, take so long to appear on the market? We believe it is due not merely to the techniques being closely guarded by those who acquired them, but also to the difference in skill levels required by in-body compared to mantle cultivation. Limiting the output also enabled most of the product to be sold with "Japan Origin" stated or implied.

Chinese akoya pearl cultivation began at least 10 years earlier, and also developed much more slowly than freshwater pearl cultivation. As they are no longer marketed as such, efforts were either abandoned, or the crop sent to Japan for processing and marketing as Japan akoye.

Bead-nucleated Chinese pearls that were probably in-body cultivated were purchased by Pacific Pearls in 2000, long before the first flame type bead-nucleated pearls appeared. One example, dyed black, inspired Fred Ward to bisect and photograph the pearls (see image below).

His focus was mainly on the presence of a shell bead nucleus. GIA had just published a report, based on x-raying tens of thousands of pearls (from a single supplier) over several years, and concluding that no bead-nucleated pearls were made in China.  Unfortunately, he made no shots of the surface, the texture of which was my clue that it is in-body nucleated. At this point in time, I had yet to encounter and to learn about flame-type in-mantle bead nucleation... which was never a significant product of Japan freshwater pearl cultivation. </p>

<p>We were frustrated because suppliers who occasionally offered in-body nucleated pearls called them yǒu hé zhū 有核珠 (having nucleus pearl) just like the flame type, and seemed not to have a term to describe the in-body pearls. Finally we learned that one supplier described his rough baroques as mǎo pí 毛 皮 (hairy skin). Incidentally, rosebud pearls with many little bumps on the surface are called máo zhū 毛珠 (hairy pearls). Another vendor calls in-body baroques mǎ pí 馬皮 (horse skin), yet another má pí 麻皮 (hemp-skin).  A more vivid term is yáng méi 楊梅 a heavily textured fruit known as a waxberry or red bayberry.  One vendor is known for  naming them "Edison" pearls, and another announced they shall be known as "Ming" pearls, at any rate a Chinese word that most foreigners can remember.  It is important not to fall into the trap of using trademarks to describe pearl types (as I observed GIA representatives doing in 2023).  A success of some brilliance was attained with the "Kasumiga" brand some fifty years ago.  Only trademarks' owners may decide whch products can be given that name.  Non enforcement however encourages its use as a generic name or provenance, creating an advantge for them.

The most relevant naming we can find for this type of pearl remains in-body bead nucleated.

We purchased similar pearls on several occasions between 1998 and late 2007, though quality tended to be poor. Imagine our surprise when we were suddenly offered not just beautiful varicolored baroques, but in a size rarely if ever attained in Japan! The price of course was also a world record, allowing us only to pick the biggest and best. The larger of 2 strands pictured measures 16.4 x 14.6mm in brilliant goldy colors, and was featured in David Federman's "Gem Profile" column in April 2008 Modern Jeweler magazine. As the article points out, this strand reveals capabilities previously unknown, and makes it reasonable to expect similar, and even more desirable products to follow. David also reviewed flame-type pearls, giving them the name "fireballs".

Read about Flame pearls, an exclusively Chinese product here.