What’s the Difference Between a Certificate of Pearl Identification and a Pearl Grading Report?

The Pearl Institute Co., Ltd is another highly reputable pearl certification organization in Japan.

 What’s the difference between an Certificate Of Pearl Identification and an Pearl Grading Report?

 Certificate Of Pearl Identification: This only verifies whether the pearl is natural or cultured and does not indicate its quality grade. The content of the identification certificate is relatively simple. Looking at sample certificates from two organizations, we can see that they include the product name, size, and an image of the submitted sample.

 The image below shows an identification certificate from the Pearl Institute Co., Ltd.

The next image shows an identification certificate from the Pearl Science Laboratory.

Pearl Grading Report: Similar to diamond grading, this certificate classifies the quality of pearls based on a well-established evaluation system. It typically involves the use of precision instruments such as microscopes, spectral analysis, translucency tests, X-ray examinations, luster assessments, and interference color checks.

Pearl Institute Co., Ltd

Founded in 1998, the Pearl Institute Co., Ltd is currently the largest organization in Japan for issuing pearl certification. The institute strictly defines "Hanadama" based on six key elements, clearly presented in a grading chart on the certificate for consumer understanding. Their innovative artistic certificate design has also received high praise. Simplified and smaller versions of certificates can be created to meet different requirements.

The Pearl Institute Co., Ltd places special emphasis on "layering," believing that measuring the thickness of the pearl layers alone is insufficient to assess their quality. Akoya pearls are formed from layers of calcium carbonate crystals. Thickness measurement only indicates the total thickness of these crystalline layers and does not reflect the thickness of each layer or the number of layers. Does the thickness and number of layers affect the luster of pearls? Yes, it does. For example, an Akoya pearl with a layer thickness of 0.4 mm, when cut open, may show that some pearls with thicker, fewer layers do not achieve the expected high luster. In contrast, some pearls with thinner, more numerous layers exhibit better luster.

 Therefore, the Pearl Institute Co., Ltd advocates for a comprehensive assessment of the density and structure of the crystalline layers, rather than relying solely on thickness measurements to determine pearl quality.

To meet the "Hanadama" standards set by the Pearl Institute Co., Ltd, all five items marked in red in the sample identification certificate must achieve level "I," which includes: 1) layer quality, 2) shape, 3) luster, 4) blemish level, and 5) uniformity of color and processing quality, all reaching the highest grade. It’s important to note that even if all five indicators achieve the highest level, there may still be cases where the institute does not recognize them as Hanapearls, so it’s essential to confirm the notes indicated in blue. The image shows: Confirmation of Hanadama.

Additionally, when both "flaw" and "finishing & matching" are rated as grade "Ⅱ" while all other aspects are rated as grade "Ⅰ", the comment section will include notes such as“花珠真珠の範疇と認めます (recognized as falling within the Hanadama pearl category)”or“花珠真珠に準じます (equivalent to Hanadama standard)”.