Learn More About Pearl Science Laboratory (PSL) of Japan

First of all, let's talk about Pearl identification agency in Japan.
The most familiar "Pearl Science Laboratory" was founded in 1987 which is the second largest authoritative appraisal organization in the Japanese pearl industry. Pearl Science Laboratory has a complete and rigorous system standard for the identification and classification of Akoya pearls and South sea pearls. Be sure to show consumers the quality of pearls objectively and in detail.
japanese hanadama necklace
By the way, most of the certificates I found were in Japanese, because my products are basically from Japan companies, so the certificates are in Japanese. But I also found a few English certificates and put them together for comparison.
hanadama akoya necklace
Here attached the website of Pearl Science Laboratory, and you guys who are good at Japanese can read them by yourselves.
Let's interpret the contents of the certificate.
The content on the left is from top to bottom: Pearl image, certificate number, pearl type, jewelry style, pearl size, and identification method.

The contents on the right are in order from top to bottom: Special Appellation, Thickness of Nacre, TERI Analysis, Brightness, Iridescent Color, Body color, Inperfection & Surface, Shape. The left side of the last column is the quality grade mark; the right side is remarks. The main information is the interference color image under the exposure of a professional instrument. Other information, for example, the first item is natural color, the second item is the inherent color of pearl layer. These two assessments depend on the circumstances. If the pearls are natural in color and your company asked to require natural in color certification, these two items will be added to the remarks column.

Speaking of grade markers, there are many gradations for Pearl Science Laboratory. We just need to remember the following two marks.

teri strongest luster

The mark on the left is the "highest quality" mark, and the mark on the right is the "strongest luster" mark. As long as these two marks are possessed, it is the highest quality pearl with the highest quality or the highest luster assessed by Pearl Science Laboratory certified.

As shown in the figure, here we explain the grade of certificates.

⭐Identification report of type - P

Type-P identification certificate is special for "Aurora tennyo". The report describes TERI’s inspection result and attached aurora image. It is a kind of "Aurora Hanadama" in a broad sense.
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⭐Identification report of type - S

Pearl identification type - S, the highest quality of all kinds of mother oysters.There are also comments on natural colors and so on, the thickness of pearl layers were measured by X-ray.

hanadama akoya necklace


⭐Identification report of type - K

Pearl identification of type - K is another grade except for the highest quality certificate. It is mainly used in the "Strongest TERI" series. The report records the quality check of 5 items including the thickness of nacre.


⭐Identification report of type - J

Pearl identification of type - J is another lower grade except for the highest quality certificate. It is mainly used for the "Strongest TERI" series. Quality analysis is concerned about the pearl luster.

⭐Identification report of type - BA

Pearl identification of type - BA has no grading instructions, only to prove that is the genuine pearl.

So much for today's interpretation of Pearl Science Laboratory. Please feel free to leave a comment if you have any questions.


  • Takaramonobr

    Japan Pearl Export And Processing Cooperative Association, their certificate name Certificate of Specially Selected Pearl.

  • Marina

    So PSL is the second largest authoritative appraisal organization in the Japanese pearl industry. Which one is the first?

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