How Can You Tell If a Diamond Is Real?
You found an old ring in a jewelry box. Or maybe you bought a piece online and it looks a little too perfect. The question appears in your mind: "Is this diamond real?"
The internet is full of DIY hacks, including scratching mirrors, breathing on the stone, and dropping it in water. But here is the truth: most of those "tests" are unreliable, and some can actually damage your jewelry.
As your trusted jeweler with years of expertise in the diamond industry, we are here to separate the science from the myths. Here is how to truly tell if a diamond is the real deal.
What Counts as "Real"?
Before you test, you need to know what you are looking for.
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Natural Diamonds: Mined from the earth. (Real)
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Lab-Grown Diamonds: Created in a lab but chemically identical to mined diamonds. (Real)
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Simulants: Cubic Zirconia (CZ), Moissanite, or Glass. (Not Diamond)
Note: A standard diamond tester will identify both Natural and Lab-Grown stones as "Real" because they are the same material.
Test 1: The "Read-Through" Test (Safe for Loose Stones)
If you have a loose stone (not set in a ring), place it face down on a piece of newspaper or a page of a book.
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If you can read the letters: It is likely fake (Glass or CZ). These materials let light pass straight through.
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If the letters are a blurry, white scramble: It is likely real. Real diamonds bend (refract) light so intensely that you shouldn't be able to see through them clearly.
Test 2: The "Doubling" Test (Requires a Loupe)
Grab a jeweler's loupe (or a strong magnifying glass) and look at the "facets" (the flat surfaces) on the top of the stone.
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If the facet edges look doubled: It might be moissanite. Moissanite is a popular diamond simulant, but it is "doubly refractive," meaning it creates a double-vision effect on the edges.
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If the edges are singular and sharp: It is likely a Diamond (or CZ).
Test 3: The Fog Test (The Quick Check)
Hold the stone in front of your mouth and breathe on it like you’re fogging up a mirror.
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If the fog stays for a few seconds: It’s likely a fake. Glass and CZ hold onto heat and moisture.
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If the fog clears instantly: It’s likely real. Diamonds are incredible heat conductors and disperse the moisture before you can even blink.
The Only Test That Matters: The Certificate
While home tests are fun, they are never 100% accurate. The only accurate way to know if your diamond is real is to check its paperwork. Real diamonds, whether natural or lab-grown, should be certified by a reputable lab like GIA or IGI. This report maps out the stone’s exact weight, cut, and identity.
At Zen Diamond, we don't make you guess. Every diamond we sell comes with certification, so you never have to breathe on your ring to know it's forever.
