Getting to know Pearls, the Kasumiga Pearl in Particular...


I was recently visiting my pearl supplier to purchase a beautiful Tahitian circle strand with an exquisite peacock green that I had seen a few days earlier and had asked him to hold it.
It is exquisite and a great price, and, as it has happened multiple times, I saw this amazing creature, an incredible strand on his desk that immediately started calling my name as soon as I saw it.  😊



Don’t laugh, the necklace knew I speak pearl and it demanded for me to take it with me. 😊

This is the first and only time in my life I had ever seen such an amazing wonder. The shape, the colors, the overtones…


“This is a Kasumiga style strand” my supplier said.
“Kasu- what?” I responded.

Since I had never seen or heard of it, I had to investigate.

After trying, (with very little luck) to research it, I felt compelled to write a small blog post about it.

In the world of pearls, since natural pearls are extremely rare, most pearls on the market are cultured, and there are two main types of pearls.
Akoya pearls and freshwater pearls.
Akoya pearls come from the ocean, mainly from Japan, but not all pearls from Japan are from the ocean, there too, they have been culturing pearls in lakes since 1935.

Here is the process of culturing pearls according to GIA
(the Gemological Institute of America)

Natural Pearls:
Natural pearls form in the bodies, or mantle tissue, of certain mollusks, usually around a microscopic irritant, and always without human help of any kind.

Cultured Pearls:
The growth of cultured pearls requires human intervention and care. Today, most of the mollusks used in the culturing process are raised specifically for that purpose, although some wild mollusks are still collected and used.

To begin the process, a skilled technician takes mantle tissue from a sacrificed mollusk of the same species and inserts a shell bead along with a small piece of mantle tissue into a host mollusk’s gonad, or several pieces of mantle tissue without beads into a host mollusk’s mantle. If a bead is used, the mantle tissue grows and forms a sac around it and secretes nacre inward and onto the bead to eventually form a cultured pearl. If no bead is used, nacre forms around the individual implanted mantle tissue pieces. Workers tend the mollusks until the cultured pearls are harvested.

Enter the Kasumiga Mystery
According to an article in GIA, they started culturing in Lake Kasumigaura in the Ibaraki Prefecture in 1962.
Today the annual production of large nucleated cultured pearls at Lake Kasumigaura is below 40 kg, a small portion of which are supplied to the international market.

This glamorous type of freshwater pearl from Lake Kasumigaura is called the Kasumiga pearl. This lustrous baroque and round pearl variety was under threat of demise before it became a major contender in the trade. Those who know about these luminous orbs serenade their admiration.  

These exotic gems were certainly not a household name, but they did offer consumers a rare variety to consider. Japanese freshwater pearl farming started in Lake Biwa, Japan in 1935 and was once a thriving business, but nearly succumbed to extinction by pollution in the 1970s.

The Japanese resurrected the industry in Lake Kasumigaura around the turn of the century, by bead nucleating local mussels; however pollution threatened the niche industry there too, so they’re have been a few local Chinese pearl farmers that are producing the same baroque style and shape as the ones from lake Kasumigaura with the same purple-bronzy luster.”

I believe it’s their asymmetrical form that incites people’s admiration to these works of art from Mother Nature.

These freshwater Kasumiga Style pearls come from the same type of mollusk as the Kasumiga but are grown by the local farmers.
There are folks who compare them to Fireball pearls, but the unique, baroque shape of the Kasumiga style is better suited for necklaces.

Although these exciting pearls aren’t specifically from Lake Kasumigaura, they are just as beautiful and rare.




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