Naming Pearls


Understand that there is no watchdog organization interested in enforcing correct pearl nomenclature, even of terms accepted by a majority of gem labs. There is nobody concerned about truth in advertising pearls, as evidenced by the existing free-for-all.


People all over the world use this word to describe certain kinds of pearls, most of which have similar free-form shapes, but may mean different things. Use of the word keshi without mention of provenance or shell type or species is therefore confusing. If we speak of black-lip southsea keshi, Japan akoya keshi or China freshwater keshi, there is little or no ambiguity.

The most inclusive definition of keshi as applied to pearls is the one used in Japan: it simply requires that the pearl so described have no nucleus. Using this definition, the majority of China freshwater pearls are keshi; all except for coin pearls and bead nucleated pearls.

Uses of 介子 keshi in Japanese include the poppy plant 罌粟 ouzoku and the genus Papaver, especially the seeds. Pronounced kaishi, the same word means rapeseed (canola) and mustard seed. It came into use for pearls as a simile for non-nucleated by-products of akoya pearl cultivation, which are most often tiny and grey.

The widest consensus among pearl traders in consumer countries probably favors limiting the use of keshi to pearls from saltwater cultivation, if only because these were known as a product a few years before freshwater pearls. Since indistinguishable keshi pearls may occur due to attack by animals boring through the shell, impacts that force shell splinters into mantle tissue, cultivation mishaps where the mantle tissue graft becomes separated from the nucleus, and by deliberate cultivation, it is necessary to classify them with cultured pearls.

Chinese traders use keshi to describe only some kinds of freshwater non-nucleated pearls – generally those we describe as second harvest (Cantonese) Choi Sang Chue: 再産球  (again born pearls/gems), and inevitably also as China freshwater keshi. A similar compound, Choi Sang 再生 (again life) means recycled. The resemblence between non-nucleated ocean pearls and second harvest freshwater is far closer than between bead nucleated baroque pearls from the same cultivations. Selected and appropriately dyed freshwater second-harvest pearls may require careful inspection to distinguish them from ocean keshi pearls.

Because the visual similarity between these products makes use of the same name practically inevitable, and because keshi has been in widespread use for some types of freshwater pearls for decades, we believe it is futile to seek to ban this use now. Provenance eliminates most ambiguity, and stating at least shell type is necessary as well to distinguish between varieties of ocean keshi. Most freshwater pearl dealers will continue to use it, and most of our customers would consider it an imposition if we asked them to use a different term for pearls they know as keshi. We use “China freshwater second harvest” by preference, but by objecting to the use of keshi we erect a barrier to comprehension.


This word was originally used as a provenance, and served as the name for all types of cultivated freshwater pearls as long as Japan was the only source. It is therefore more difficult to justify the use of Biwa to describe certain types of Chinese pearls. Nonetheless, it is worth noting that Chinese dealers use the word to mean non-nucleated pearls of of flat, elongated shape we call sticks.

Stick pearls are made by inserting long strips of active mantle tissue into the outer mantle, usually folded in half. This allows an elongated pearl sac to form quickly. Lake Biwa produced pearls like these regularly for some years, so it is possible that a technique learned from there is being acknowledged. They have been available for many years, and it is from pairs and groups of closely-spaced stick pearl sacs merging together that more or less flat non-nucleated second-harvest pearls reaching impressive size are harvested.

Lake Biwa, near Kyoto, Japan was the center of freshwater pearl cultivation, and is home to a handful of diehard, burt reportedly unsuccesful cultivators to the present day.. Its name is a Chinese word. 琵琶 Pipa is the name of a traditional Chinese stringed instrument, and has been used to describe certain types of freshwater pearls in Chinese language invoices.

The Hong Kong Government in the 1980's refused to allow an acquaintance to register “Biwa Pearls” as his trademark. He had to settle for “B.wa Pearls”.

Kasumiga, on the other hand, is a registered trademark created by truncating another Japan freshwater pearl provenance, Lake Kasumi-ga-Ura. Perhaps because the most conspicuous early advertising for Japanese freshwater pearls was made with this trademark, a number of experts mistakenly believe it is a provenance or at least a generic name for Japan freshwater pearls, just like Biwa.

Japan freshwater pearl production, Biwa and Kasumi-ga-Ura areas combined, cease in the mid-1980's,  The phoenix that rose from the ashes in the Kasumi-ga-Ure area is vestigial in scale. Since few of the products called Biwa actually originate in Japan, we describe our antique Japan-origin pearls as “Lake Biwa” or “Japan Biwa”. Non-nucleated Japan-origin freshwater pearls were practically all made before 1980. The reason: Chinese pearls of this type were so plentiful by this time that it does not make sense to expend mussels nacre producing capacity for any but in-body bead-nucleated pearls.



Kasumi-ga-Ura is of course a detailed provenance of very small quantities of Japan freshwater pearls.  We call them Japan Kasumi pearls, to disambiguate the provenance without requiring people to learn too many foreign syllables.  

Kasumiga is a trademark, which was for a long time mistaken for many with a provenance;  but of course it is the prerogative of an owner to choose products bearing that name.

Japan origin freshwater pearls were originally non-nucleated.  They were hardly know in Europe or the Americas, but exported mainly to India.  Due to their similarity to Mediterranen, Persian Gulf and Black Sea pearls, OPEC countries absorbed all that Japan could produce.  Since Chinese production of non-nucleated mushroomed in the 1970's, Japanese production rapidly became limited to in-body bead nucleated pearls.

A scientific test to prove freshwater pearls’ provenance has been developed in Germany, with samples provided by Perlen Yukie GmbH, the German company of the Dillenburger -Demiya family, who also marketed genuine Japan Kasumi pearls. It compares concentrations of Strontium and Barium found in freshwater pearl nacre. I do not know how many pearls have undergone this destructive test, but this does not appear to be a simple solution to proving provenance.

Pacific Pearls has keenly pursued the state of the art of bead-nucleated pearls from China. We have long been convinced that IBN pearls have been produced in China since at least ca.1990. Now that they have appeared in quantity, there can be no more doubt that China has this capability, and that gradually higher quality large pearls can be anticipated.  Exceptionally large and/or round pearls have proven serious competitive alternative to Southsea pearls produced in Australia, Tahiti, Philippines and numerous other places in the Pacific Ocean.

The incomparably large scale of Chinese IBN production leaves no doubt as to availability of pearls with colors and surface textures typical of Japan Kasumi pearls.  We are glad to be able to offer variations of a much-loved look at far more affordable prices.  But their relative scarcity suggests that the demand from vendors who state or imply Japan origin is still strong.

Pacific Pearls sells many times as many China origin pearls, all with the correct provenance, and differentiates between cultivation methods to the best our ability, which few competitors attempt.  China has ushered in a Golden Age of diversity in Freshwater Pearls;  I have no recent statistics to hand, but they must have exceeded half by value, and 99% by weight.

In stark contrast, Japan freshwater pearl production has again dwindled to a single active operator.   We are committed to his support as long as we are both in business,.



This is a truncation of 池蝶貝 ikechou-gai, the Japanese name of the traditional freshwater pearl mussel, Hieriopsys schlegeli. We have seen it used for different types of China freshwater pearls, mainly bead-nucleated (in-body as well as flame type). The latter case is probably due to an inability to differentiate between types, but in the former it appears to function as a buzzword, like a freely usable trademark that explains the pearls’ disctinctive appearance.

We are not comfortable with the implication that the pearls are cultivated using pure-bred H. schlegeli mussels. Although some individuals survive, most cultivation areas require a more resistent hybrid. Probably a great number of hybrids are in use, and not all genetics may be accurately recorded. Since it does not address the issue of cultivation method, we feel this usage is confusing. We offer IBN: in-body (bead) nucleated pearls as a more informative name.