Kasumi pearls from Japan's Misty Lake

Kasumi pearls from Japan's Misty Lake Organic

Kasumigaura is the name of a lake in Japan, the name of which translates as "Water covered with mist". It is here that Kasumi pearls are grown, which sometimes cost more than Tahitian black pearls.

Lugano ring with natural Kasumi pearls. Image source: luganodiamonds.com


Although the current global market for freshwater cultured pearls is largely dominated by Chinese products, freshwater pearl culture in Japan began in 1935. Biwa Lake in Shiga Prefecture supplied pearls of a wide variety of colors to the domestic and international markets until 1982. Due to water pollution and the depletion of Hyriopsis schlegelii, some pearl farms were relocated to Lake Kasumigaura in Ibaraki Prefecture starting in 1962.

Today, Lake Kasumigaura's annual production of coarse-grained cultured pearls is less than 40 kg, a small part of which is supplied to the international market.

Kasumi pearls from Japan's Misty Lake

In Japan, freshwater pearl cultivation began in the Meiji era (1904–1912) with Tatsuhei Mise using Cristaria plicata on Lake Kasumigaura, followed by Tokujiro Koshida's experiments with Margaritifera laevis on the Chitose River in Hokkaido, but both trials ended in failure.

Masao Fujita carried out a number of experiments in and around Lake Biwa and succeeded in commercial cultivation of freshwater pearls using Hyriopsis schlegelii in 1935. Its breakthrough was interrupted by World War II, and with the resumption of culture operations, there was a shift from nuclear to non-nuclear pearls, which eventually formed the basis of modern freshwater pearl culture.

These Biwa pearls show good brilliance, unusual color and shape. The mollusc Hyriopsis schlegelii has been used to grow nuclear-free freshwater cultured pearls in Lake Biwa since 1935. Photo by Satoshi Furuya. Image source: gia.edu

Kasumi pearls from Japan's Misty Lake

One of the characteristic features of Kasumiga pearls (as the Japanese began to call Kasumi pearls to distinguish from the Chinese counterpart) produced by a hybrid mollusk is its color.

Photos by Tetsuya Chikayama. Image source: gia.edu

Kasumiga pearls are available in cream, light yellow, pink, purple, orange and gold, ranging in size from 9,5 to 19,6 mm, round and baroque. They were obtained after a cultivation period of two to four years.

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The variety of colors includes white, pink, magenta, yellow, purplish red, orange and iridescent brown.

Kasumi pearls from Japan's Misty Lake

Kasumiga pearls are usually not bleached or dyed.

The pink and purple colors of Kasumi are especially expensive. In the US and Europe, Kasumiga pearls are highly valued for their brilliance, variety of colors and size, and supply has not kept pace with demand.

Kasumi pearls from Japan's Misty Lake

In the production of Kasumi pearls, the Japanese were overtaken, as usual, by the Chinese. The fact is that the cultivation of pearls is a process that damages the environment, so the Japanese limit farms. Well, Chinese breeders are not so scrupulous.

The photo shows examples of Chinese Kasumi pearls:

Kasumi pearls from Japan's Misty Lake