Japan Kasumi Pearls

Freshwater pearls from Japan’s only current pearl-producing lake.

top 2015 Japan Kasumi harvest -pro shot 2961

pair of japan kasumi pearls 622

Japan Kasumi pearls are large freshwater pearls with a shell bead nucleus. They are cultivated in the upstream areas of Lake Kasumi-ga-Ura, some 40 miles northeast of Tokyo. (Kasumi-ga-Ura roughly translates to “the body of water beyond the mist”.) Three men remain active in a craft that employed many hundreds during the 1960’s and 70’s.

A far cry from the white, round, near-perfect pearl ideal, Japan Kasumi baroque pearls are appreciated by a minority who choose character over perfection, individuality over uniformity, and splendid, natural colors over the absence of color.

fuji and sarah kasumi    torerakasumi 1

Japan Kasumi pearls are cultivated in a hybrid freshwater mussel, which is a cross of the Hyriopsis cumingii / Hyriopsis schlegelii species. The sizes of the pearls range from 9-13mm, although most are between 10-12mm. Baroque pearls from this production often have a unique “rippled” surface, which has helped make them a relatively common name to pearl enthusiasts world-wide.

Naturally occurring, brilliant colors and “oil-slick” luster have further proven to some that these pearls are worth the difference in price from their Chinese counterparts. Japan Kasumi pearls are found in shades of white, cream, orange, peach with various shades of pink, and even sometimes a golden-green. The most prized color is deep-purple.


These freshwater pearls are not given any treatments after harvesting. They are simply rubbed with salt to clean them, rinsed and prepared for export.

As this is a very small production, we often wonder how many pearls we will be able to offer each year. The lake has had a history of problems with both pollution and naturally occurring amoebic invaders, making the farmers’ jobs increasingly difficult. These factors add to the price paid per pearl. Again proving their rarity, a strand of our Japan Kasumi pearls was included in the Museum of Natural History Pearl Exhibit, which, since 2001, has toured around the world.

Kojima Company has carried Japan Kasumi pearls since 1995. We love making strands for an increasing number of enthusiastic customers. These pearls are quite rare and often misunderstood in the market; therefore we enjoy educating our customers about their unique origins. We offer a packet of literature to anyone who is interested in reading more about Japan Kasumi pearls. Please feel free to contact us and we will send it to you in the mail.


If you are interested in downloading more information on Japan Kasumi pearls… please click here to access the article written by Fuji Voll of Pacific Pearls.

Japan Kasumi PDF


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