How to Read a Pearl Science Laboratory Certificate
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.
What Is a PSL Certificate?
Pearl Science Laboratory (PSL) is one of the most respected pearl grading laboratories in Japan.
Their certificates are commonly used for:
- Akoya pearls
- Aurora Hanadama pearls
- Aurora Tennyo pearls
- South Sea pearls
- Tahitian pearls
Unlike basic pearl authentication reports, PSL certificates focus heavily on grading and pearl quality analysis.
The Left Side of the Certificate
The left side contains the identification details of the jewelry piece.
This section usually includes:
- Pearl image
- Certificate number
- Pearl type
- Jewelry style
- Pearl size
- Testing method
This part mainly confirms what the jewelry actually is.
For example, it will specify whether the pearls are Akoya, South Sea, or Tahitian pearls, along with the pearl size range.
The Right Side of the Certificate
The right side is where the quality analysis happens.
This section is the most important part for collectors and experienced buyers.
Depending on the certificate type, you may see:
- TERI analysis
- Nacre thickness
- Brightness
- Body color
- Iridescent color
- Surface quality
- Shape
These categories help evaluate the actual beauty and quality of the pearls.
What Does TERI Mean?
TERI is one of the most important terms in Japanese pearl grading.
In simple words, TERI means pearl luster.
High TERI pearls have:
- Sharp reflections
- Bright glow
- Mirror-like shine
This is one reason why high-quality Japanese Akoya pearls often appear so bright and reflective under light.
In many cases, strong luster is considered even more important than perfectly flawless surfaces.
How to Verify Natural Color Pearls
If you're shopping for grey Akoya pearls, this section becomes extremely important.
Many grey pearls on the market are artificially irradiated or color-treated.
On some PSL certificates, you may see remarks stating that the pearl color originates from organic sources within the nacre layer.
This indicates the pearls are naturally colored rather than artificially treated.
For collectors seeking natural-color grey Akoya pearls, this small note can make a very big difference.
What Are “Aurora Hanadama” and “Aurora Tennyo”?
These are special grading designations used by PSL for high-quality Akoya pearls.
Aurora Hanadama pearls are already considered premium-grade Akoya pearls.
Aurora Tennyo pearls are an even higher classification with exceptional luster and stronger interference colors.
These grades are highly respected among Japanese pearl collectors.
What Is the Most Important Part of the Certificate?
For most experienced buyers, the most important factors are:
- Luster (TERI)
- Natural color verification
- Nacre quality
- Overall matching
While surface flaws and shape matter, exceptional luster is usually what separates ordinary pearls from truly beautiful Akoya pearls.
Final Thoughts
At first glance, Japanese pearl certificates can look intimidating.
But once you understand the structure, PSL certificates become extremely useful tools for comparing pearl quality.
Whether you're shopping for Aurora Hanadama pearls, natural grey Akoya pearls, or simply trying to understand Japanese pearl grading, learning how to read a PSL certificate helps you buy with much more confidence.
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