Japan Kasumi-ga-Ura Pearls

Japan Kasumi-ga-Ura freshwater pearls are being cultivated in 2016 by only three operators. Since the mid-1980's, they and a handful of families in the Lake Biwa area are the only active freshwater pearl cultivators in all of Japan. Some have no pearls to harvest this year, others only mediocre qualities. With the best luck imaginable, their combined production volume will remain minimal... that it has not vanished altogether is due only to their individual dedication to their craft. Japan freshwater pearl production, most noted for its many participants in the Lake Biwa area, employed thousands of people during the 1970's and early 80's.  Biwa pearls were a synonym for freshwater pearls for decades. Environmental conditions in the late 1980's brought all efforts to an end. The re-establishment, albeit on a minimal scale, of production in the Kasumi-ga-Ura area (some 40 miles northwest of Tokyo) defied environment and marketplace alike. Chinese production of most FW pearl types except bead-nucleated had seen a lot of progress by the early 1990s. All types of cultivation except in-body bead nucleation were abandoned at this point because the market price of the pearls they yield could not cover production costs in Japan. A bigger challenge to this cottage industry's survival is the suddenly widespread availability in 2010 of  in-body bead nucleated  freshwater pearls from China.   Available quantities had for the preceding two decades had been limited, allowing many to be sold with "Japan origin" stated or implied.  

X-rays confirm that this type of bead-nucleated pearl has through-drilled nuclei, a requirement of Japan-style in-body nucleation.   Made the same way, also using a Hieryopsis schlegeli/cumingii hybrid, these pearls naturally have more similarities to Japan Kasumi pearls than to China Flame pearls.   There are differences between Japan Kasumi harvests from individual producers and in various years;  yet there can be no more doubt that China has this capability.  In the midst of a shakeout of marginal pearl producers with other manufacturing industries competing for workers,  is is hard to predict how rapidly;  we believe there will be much higher quality bead-nucleated pearls from China in future using in-body bead nucleation.

Pacific Pearls imported a considerable portion of the baroque pearls harvested in the Kasumi-ga-Ura area since 1992. Enthusiasts competed for those with the most unusual colors. Since the blight of 2003, which caused the loss of some 80% of Japan Kasumi pearls being cultivated, the baroque component of each year's harvest was much smaller. Since smoother pearls fetch higher prices in most markets, a scarcity of baroques is not per se a disaster for the cultivators. However, the strong colors we admire in the baroques do not occur in the higher, ie smoother qualities. Even those mussels which were exposed to the bad water before being operated sustained permanent damage, and produced considerably less nacre than expected in the 3 to 4-year period.   In 2010 the there were more baroques harvested than in nearly a decade, from mussels that were never exposed to the blight.  Still, the death rate is rising, and farmers are eager for new genes to produce more resistant hybrids.


Japan Kasumi-ga-Ura pearls - in depth

Pacific Pearls Co., Inc. (founded 1951 in Japan) was an early exporter of akoya pearls and of Japan freshwater pearls. In recent years, we have exported to the US many Japan Kasumi pearls. They are bead-nucleated, in-body cultivated freshwater pearls. Our subspecialty is the baroques, some of which occur in intriguing natural colors not often found in pearls from other sources, nor even in smoother, rounder pearls from the same source. Read more in detail about in-body cultivation (page 3) and in detail about natural colors (page 4). Japan Kasumi pearls, as I suggest we call them to avoid the slightly cumbersome full name of their geographical source, are perhaps an environmental "miner's canary", felicitously surviving in the face of overwhelming odds. They vanished along with Lake Biwa freshwater pearls during the 1980's following a losing battle with crop spraying, anoxia and factors that remain riddles. They reappeared almost a decade later, in a world that had changed dramatically with the progress achieved meanwhile in China. Read more in detail in about naming. Many collectors and jewelry designers appreciate the distinctive appearance and limited availability of Japan Kasumi baroque pearls we offer, despite their inevitably high price compared to Chinese flame-type bead-nuc, Tahitian baroques, or other pearls of roughly comparable size, shape and surface. This suggests the operation of a method of valuation that deviates from the smoother -rounder-whiter grading paradigm developed for akoya pearls. See akoya pearls for a discussion of akoya valuation criteria. Perhaps a sea change toward appreciating character and relative uniqueness in cultivated pearls instead of uniformity and degree of "un-naturalness" might benefit pearls' image. Lake Kasumi-ga-Ura never hosted more than an obscure and minor pearl cultivation, serving first as a source of mussels the more numerous and longer-established cultivators in the Lake Biwa region. This occurred both when abundant wild mussels (possibly introduced during the 1930's) were collected in the 1960's and again when a viable hybrid appeared in the late 1980's. Read more in detail about hybrid Hieryopsis schlegeli mussels  Biwa and Kasumi-ga-Ura's best years, ca.1960-80, were also very good years for OPEC, Arab members of which were prepared to absorb as much as Japan could produce of no-nucleus freshwater cultivated pearls. Few people in the western world paid any attention to freshwater pearl cultivation then. However Robert Crowningshield did, and his article in the Spring 1962 Gems and Gemmology contains immense knowledge and insight. I recommend it for study by all serious students of pearls.   It was accompanied by an x-ray photograph much like the one below made in 2011 of China in-body bead-nucleated pearls, revealing two drilled channels in every pearl. Read more in detail about in-body bead-nucleated China pearls non-nucleated pearl cultivation   

Lake Kasumi-ga-Ura tributary pearl farming is practiced by only five small producers in the region. I was introduced to their de-facto spokesman, Kazuhisa Yanase (Yanase Pearl Co, Ltd) by Fusako Uda, a friend of my family and the late Seiichiro Uda's (9) daughter. In 1991, Yanase harvested his first pearls following a decade during which enough mussels could not be kept alive. Its total volume fit easily in his hands. In 2003, a blight officially blamed on carp herpes wiped out most carp (koi) in Japan, and most fw pearl cultivation except Kasumi-ga-Ura ended. By some unprecedented fluke, only 80% of unharvested pearls were lost there. In 2008, Yanase and a few others continue to run tiny operations. Read more in detail about current producers and about freshwater pearl pioneer Seiichiro Uda (page 9). Only months away from becoming the first man to cultivate pearls in a pond, Mr Yanase suffered a setback in 2001 when crabs made a hole, draining the water and wiping out all the mussels and pearls. Read more about Yanase's pond cultivation attempt

As operators' skill improves, a larger proportion of higher-quality pearls, ie smoother surface and rounder shapes, may be hoped for. Unintended phenomena such as these exotic-colored baroques we love have tended to become scarcer as a result. Baroque shape is generally accepted as unavoidable in most pearls with thick nacre coating, but probably no cultivator ever strove to produce more baroque than rounder/smoother pearls, as the latter generally fetch more. The 2003 blight eliminated baroques almost completely from 5 years of production. It is thought that mussels producing baroques are under a a greater burden than those with pearls more ideally placed for becoming smooth and round, and that most of them succumbed to the blight for this reason. Sarah Canizzaro has been with Pacific Pearls for over a decade and also trades in pearls as kojimapearl.com. She has matched, drilled and strung most of Pacific Pearls Japan Kasumi pearl strands, including one displayed in the American Museum of Natural History's "Pearls" exhibit. The first of its kind, the exhibit was very successful at numerous museums worldwide over a seven-year period.

In-body nucleation

In-body bead nucleation is used for most of the ocean pearl industry's products, Japan akoya as well as southsea, except 3/4 and mobe. Because it enables them to compete with southsea pearls, this is the only type of cultivation practiced by Japan freshwater pearl farmers since the devastation of their industry due to environmental degradation during the 1980's. On the other hand, the proportion of pearls with any shell nuclei coming on the market from China has only gradually become significant. Coin pearls, nucleated with flat shell pieces, appeared during the 1980s. Pearl-nucleated pearls, generally flat in shape, were seen sporadically since the 1990s, and bead-nucleated flame pearls have been the big news starting in 2003. Descriptions of both flame type and in-body nucleated Chinese pearls are available on pages accessed from the home page or sitemap. In each case above, nuclei are inserted into pearl sacs previously grafted in a mussel's mantle tissue, which is surgically far less demanding than placing both a nucleus and mantle tissue graft within the body itself. In-body bead nucleated freshwater pearls from China so far represent a tiny portion of total production, and to date only a few people are aware of them. The majority of China freshwater pearls remain no-nucleus. Read about non-nucleated pearl cultivation and in the detail of our page about non-nucleated (regular) China fw pearls. A curious fact of Japan Kasumi pearl cultivation is that the shell nuclei are drilled through before implantation. This is because the best technique developed for preventing the graft of active mantle tissue (which will form the pearl sac) from becoming separated from the bead requires spearing first the bead, then the graft on a sharp pointed tool for insertion into the body. When strands of such pearls are x-rayed, two drilled holes can be observed in each pearl. However, there is no reason to believe this technique would not be used elsewhere.



Japan Kasumi pearl colors are within the range typically occurring in freshwater mussels and therefore in pearls cultivated using them. Pale peach, lavender, and off-white are most common with smooth surface. Generally, only the baroques exhibit intense colors. These include both typical purple and peach hues, and uneven, blotchy arrangements of elements of brown green and gold ... which we call pond slime color. Similar, presumably natural colors are found among most types of Chinese fw pearls, including bead-nucleated. In 2007, we were first able to obtain beautiful in-body nucleated pearls from China in both intriguing colors and larger size than we have ever obtained from Japan. The more abundant "flame" type in-mantle bead-nucleated pearls are now available in a wider range of sizes and price levels. Brownish natural colors, usually unevenly distributed in blotches, were known since early Lake Biwa cultivation. We always found such colors attractive, along with certain other types of imperfections that tend to limit cost while adding greatly to a pearl's or a strand's character. We have purchased such pearls from China whenever they appeared. For many years, the pond-slime color was limited to material of such poor quality that nobody wanted to spend $50- per kilo enhancing it with black dye. Now it is available in all price ranges. Still celebrated as a novelty by many, this type of color does not normally command a premium over other colors. The exception has become Japan Kasumi pearls... since the blight of 2003, very few baroque pearls have been produced. Mostly smooth pearls have been harvested since that time, causing an acute scarcity of pearls with intense and intriguing colors.  Only in 2010 did China origin in-body bead-nucleated pearls, including textured baroques in a wide variety of natural colors, become widely available.  


We call these pearls Japan Kasumi, simply a reference to their place of origin. Kasumi-ga-Ura is a lake near Tsuchiura city, surrounded by flat farmland dotted with coin-op rice polishing machines. It is sometimes visible on the approach to Narita (Tokyo Int'l) Airport, as the first sizeable inland water near the coast north-east of Tokyo Bay. A brackish bay some three centuries ago, it silted up to become a lake. Its fauna suffered much due to agricultural chemicals, which were blamed for the failure of freshwater pearl cultivation throughout Japan in the 1980's. Kasumi means mist as in light fog, Ura an inlet or sheltered bay. They are connected by a conjunction common in Japanese place names. Pacific Pearls has never sold "Kasumiga" pearls. We caution our customers against inadvertant misuse of someone else's trademark. Even though I am unaware of any legal action taken against unauthorized users of the "Kasumiga" brand by the owners, I point this out because some people on whom many depend for precise information, such as gem lab and widely published experts, are confused about it. They use the brand name as if it were a generic or place name, to refer either to (in-body) bead-nucleated freshwater pearls in general, or to Japan origin ones in particular. In 2006, Boris Dillenburger of Perlen Yukie GmbH in Merzig, Germany, a major distributor of smooth, high-quality Japan Kasumi pearls, announced the development of a lab test aimed at differentiating between Japan and China origin freshwater pearls. Histograms of strontium and barium concentrations in the nacre are said to exhibit slightly different patterns between samples of Japan and China pearls provided to a group of biologists in Germany by Dillenburger. Pacific Pearls has purchased Chinese bead-nucleated freshwater pearls whenever they appeared on the market. For details, please see pages devoted to flame-type and in-body bead nucleated Cfw pearls, accessed from the home page or sitemap.


Hybrid Mussels

The "secret" of this success lies in the development, more fortuitous than intentional, I am told, of a more robust hybrid. Chinese Hieriopsys cumingii mussels had found their way into breeding tanks at Kasumi-ga-Ura as souvenirs of Uda's (9) and other Japan freshwater pearl pioneers' worldwide travels. Contrary to expectations, they interbred with Japanese Hieriopsys schlegeli survivors to produce an only slightly smaller mussel which proved viable in water quality prevalent in Japan today. Read more about freshwater pearl pioneer Seiichiro Uda. It is not known whether that new hybrid was successfully introduced to China, where H. schlegeli were not previously known to be available to freshwater pearl cultivators. Probably a number of different hybrids exist, and are being evaluated for suitability for the various forms of cultivation currently underway. Several sellers of Chinese bead-nucleated pearls call them "ikecho", a truncation of the Japanese word for Hieriopsys schlegeli. Since such naming is usually unaccompanied by further explanation, we are unable to evaluate its significance.  We believe that the cultivation method has more influence upon the look of the product than variations in the genetics of the mussels used.

Non-nucleated freshwater pearl cultivation

Please avoid the confusing expression "tissue-nucleated" as (active mantle) tissue is always used in pearl cultivation. Optionally, a bead or other shaped nucleus, usually made from shell, may be used. That bit of tissue forms the pearl sac that surrounds and adds nacre to the pearl. Although traces of parasites enclosed in some natural pearls may be found, no part of inserted mantle tissue can be found within a cultivated non-nucleated FW pearl. The oxymoron "tissue-nucleated" must have been created by people who first learned (rather superficially) about bead-nucleated pearls, and had no knowledge of the pearl sac... they believed the bits of tissue were inside the pearl. Non-nucleated pearls have not been cultivated in Japan since the early 1980's. Previously made as a by-product of bead-nucleated freshwater pearls, it became uneconomical to devote even a fraction of a mussel's capacity to non-nucleated pearls, which had become available in quantity from China. Pacific pearls has many old Lake Biwa no-nuc fw pearl strands and loose purchased in the 1970's. Demand is low, and we offer them at prices then prevalent. We are certain of the provenance of the pearls that we sell, but can offer no reliable method for differentiating non-nucleated fw pearls of Japan and China origin. To read about someone who may have a method, please see pearl naming. Chinese dealers have been understandably eager to exploit the familiarity of names such as "Biwa" and "Keshi" for Chinese pearls. Distinctive-looking no-nuc pearls from a second harvest, produced without any additional surgery by mussels that survive a first harvest done carefully with a scalpel, are described using one of these words more often than not. We have invoices written entirely in Chinese except for the 4 letters "BIWA" in the description field. Other suppliers write in Chinese "Pipa pearls", using the characters the Japanese use for "Biwa", actually a traditional Chinese stringed instrument. When the Hong Kong government refused to allow a clever fellow to register "Biwa Pearls" as his trademark, he settled for "B.wa Pearls". The meaning of these and other words may eventually change because a majority uses them to mean something else. In any case, with the addition of accurate provenance, these terms are fairly clear and unambiguous. Japanese dealers use "Keshi" (meaning poppy, a simile for tiny grey pearls produced as an unintended by-product of akoya pearl cultivation) to describe all non-nucleated pearls - hence including many more kinds of Chinese freshwater pearls than does its use by Chinese dealers mentioned above.


Of five operators active in the production of Japan Kasumi pearls, only three were the first to resume work in the 1990s. Some 10 other pearl cultivators hold licenses in the Kasumi-ga-Ura area, but have long abandoned efforts to re-establish production. Instead, many are engaged in litigating with government agencies for compensation for the loss of their livelihood due to the decline of water quality. Since 2004, they and a handful of families in the Lake Biwa area, are the only fw pearl cultivators active in Japan. At the end of 2008, only a few of them have any pearls ready to harvest. Photo: Shinjyu Business (Quarterly), Tokyo, Japan issue No 21 - published 20 April 1994. A copy of the article, describing the revival of freshwater pearl cultivation in Japan in the wake of the 1980's wipeout, and/or of an English translation obtained for GIA by Doug Fiske, are available by request from Pacific Pearls.

Seiichiro Uda

Seiichiro Uda (born 1893) was a Japan freshwater pearl cultivation pioneer. Neither a scientist nor a skilled surgeon (like Mikimoto 4 decades earlier, he hired people with those skills) he was an enterpreneur bent on leading the field with a new product, with access to resources needed to overcome numerous obstacles. Uda hired Kazuhisa Yanase because he had met Yanase's older brother in Brazil. Uda and a few others travelled extensively, acquired mussels wherever possible, and carried live specimens home, wrapped in wet newspapers in hand luggage. Breeders have experienced that mussels from distant habitats are usually incapable of interbreeding. For more detail, see hybrid Hieriopsys schlegeli mussels. Uda attempted to establish fw pearl farms in several other countries including the US, but succeeded only in Japan. A big player in the field, his company succumbed after the 1980's wipeout. Seiichiro Uda, economic pioneer of the postwar era, and on location in Thailand.               Bottom photo taken at Uda's farm in the Lake Biwa area circa 1968, Kazuhisa Yanase (back to camera) and Harou Uda (Seiichiro's nephew) harvest freshwater pearls, watched by Fusako Uda, Aloha Voll, and Frieda Voll.

Pond Cultivation

Yanase's pond was near his breeding pool, just across the dyke from his main mussel-holding area at the mouth of the Sakuragawa river. Breeding juvenile mussels (raising spat) has been done in pools for years, but adult, especially pearl-operated mussels have needed natural water. Using water mixed from river and tap, and chicken-manure compost to nourish plankton, a good survival rate was maintained. However, pearl growth speed lagged behind that acheived in flowing river water. No previous attempts to cultivate pearls in a pond are known. The project failed because, during Yanase's 2-day absence from the farm, crabs made a hole that drained the pond, with a total loss of mussels and pearls. This was before the 2003 blight, which decimated the carp (koi) farming and wiped out freshwater pearl farming elsewhere in Japan. By some unprecedented fluke, some 20% of pearl-operated mussels in the Kasumi-ga-Ura area survived, but the Sakuragawa site became unusable. Yanase would have moved his mussels years earlier, but was denied permits by bureaucrats, some of whom have appear to bear a grudge against fw pearl cultivators.

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