A Gemex rating shows how much a diamond sparkles by measuring light performance.
It looks at brilliance (white light), fire (rainbow colors), and scintillation (sparkle when moved).
Diamonds are rated from Low to Very High using special light tests.
A higher Gemex rating means a brighter, more beautiful diamond.
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When shopping for a diamond, most people hear about the 4Cs: cut, color, clarity, and carat. But did you know there’s another important factor that shows how sparkly your diamond really is? It’s called the Gemex rating — and it’s all about light performance.
So, What Exactly Is a Gemex Rating?
A Gemex rating measures how well a diamond reflects light. Using advanced technology, it breaks sparkle down into three parts:
- Brilliance: White light that shines from the diamond.
- Fire: Rainbow-colored flashes that sparkle in the light.
- Scintillation: Tiny flashes of light you see when the diamond moves.
The rating shows if a diamond performs at a Low, Medium, High, or Very High level in each category.
How Is a Gemex Rating Measured?
The Gemex system uses a special machine to take pictures of the diamond under five different lighting angles. This captures the diamond’s true sparkle in real conditions — not just under jewelry store lights!
The result is an easy-to-read graph that shows you exactly how much brilliance, fire, and scintillation the diamond gives off.
Why Should You Care About It?
Let’s be real — the sparkle is what catches your eye first! A diamond can score well on the 4Cs but still look dull if it doesn’t reflect light well. That’s where the Gemex rating comes in.
By checking the Gemex score, you can:
- Compare real sparkle between diamonds.
- Buy confidently, knowing the diamond will shine in everyday lighting.
- Go beyond just technical grading — and focus on beauty.
| Category | What It Measures | Rating Scale |
|---|---|---|
| Brilliance | White light reflected from the diamond | Low → Very High |
| Fire | Rainbow colors from light dispersion | Low → Very High |
| Scintillation | Sparkle or flashes when the diamond moves | Low → Very High |
Final Thoughts
If you’re shopping for a diamond, ask if a Gemex report is available. It gives you a clear, visual way to see how brilliant your diamond really is — not just on paper, but in real life.
Because in the end, what matters most is how much it sparkles on your finger