If you've ever looked at a Japanese pearl certificate and felt completely confused, you're definitely not alone.
Pearl Science Laboratory (PSL) certificates contain a lot of information, and most of them are written in Japanese.
The good news is that once you understand the layout, they're actually much easier t o read than they look.
In this guide, we'll break down the most important sections of a PSL certificate and explain what they actually mean for pearl quality.
Not all pearl certificates are the same.
Some certificates only confirm whether a pearl is genuine. PSL goes much further by analyzing details that experienced pearl buyers actually care about:
Luster (TERI)
Nacre thickness
Surface quality
Shape
Natural color verification
This is especially important for Akoya pearls because two strands may look similar at first glance, while their luster and quality can be completely different in person.
PSL certificates help buyers understand those differences more clearly.
The TEN-NYO is essentially a Hanadama but they are at the top of the grading scale.
For a strand of pearls to be considered TEN-NYO, it must firstly be certified as Hanadama.
Only after passing Hanadama standards can the pearls undergo additional Aurora Tennyo testing.
This is why Aurora Tennyo pearls are much rarer.
How to Identify Natural Grey Akoya Pearls
The most important detail on both certificates is the statement confirming that the pearl color originates from organic sources.
This indicates the pearls are natural color and have not undergone irradiation or artificial dye treatment.
What conditions do akoya have can be named as Hanadama?
Pearl body color (Numeric): below 54.7% (white series)
Gloss (Numeric) : above 6.0 (monochrome)
Surface exhibits minimal to no visible blemishes
Shape: Round ~ Symmetry
Inner Inspection – Thickness of pearl layers by optical fiber with a minimum of 0.40mm.
Diameter: ＞6mm
Certified by Japan Pearl Science Laboratory, with high degree of recognition and level of technology to certify Hanadama Pearls.
