How to Tell if a Diamond Is Real

The fog test is a hint, not proof. When you breathe on a real diamond the fog clears almost instantly, because diamond moves heat away from its surface faster than almost any other material, while many imitations hold the fog for a second or two longer. It is a quick, harmless check you can do at home, and a stone that stays foggy is worth a closer look. But it is not reliable on its own: moissanite also disperses heat quickly and can clear fog like a diamond, and results vary with room humidity and how you breathe. Treat a passed fog test as mild reassurance, never as confirmation. If it actually matters, follow up with a jeweller's tester or a grading report, which is the only way to be sure.

No, please do not. The old idea that only a real diamond scratches glass is a myth that can damage your jewellery and prove nothing. Diamond is extremely hard, but so are several imitations, and cubic zirconia or moissanite can scratch glass too, so a positive result tells you almost nothing. Worse, dragging a set stone across glass can chip the diamond at a weak point, loosen it in the setting, or scratch the metal, and you risk cutting yourself on broken glass. There is simply no upside. If you want to know what a stone is, use a proper thermal and electrical tester or check its grading report and laser inscription, both of which are safe and far more accurate than any scratch test.

Yes, a lab-grown diamond is a real diamond. It has the same chemical makeup, the same crystal structure and the same hardness as a mined diamond, so it behaves identically on a tester and looks identical to the eye. The only difference is origin: one grew in the earth over a very long time, the other was grown in a controlled setting in weeks. Because they are so alike, the law requires sellers to state clearly when a diamond is lab-grown, using words like laboratory-grown or laboratory-created, so buyers are never misled. A lab-grown diamond is not a fake or a simulant like cubic zirconia. It is a genuine diamond that usually costs less than a mined one of the same grade, which is why many buyers choose it.

Jewellers combine a few tools rather than relying on any single trick. The first is a handheld tester that checks how the stone conducts heat and electricity, which separates diamond from most imitations and, with the electrical function, flags moissanite that an older heat-only tester would miss. The second is magnification: under a loupe or microscope we look for the tiny natural inclusions and growth features that tell a real stone from glass or cubic zirconia. The third is the paperwork, matching any laser-inscribed report number on the girdle to a grading report from a respected lab. No one of these is the whole answer, but together they give a reliable result. For high-value or sentimental stones, a full lab report remains the gold standard, and we can help arrange one.

Yes. Bring any stone to our Coquitlam studio, whether it is an heirloom, a gift, or something you are unsure about, and we will tell you plainly what it is. We test it with a proper thermal and electrical tester that separates diamond from common imitations and from moissanite, then examine it under magnification for the natural features that distinguish a real diamond from glass or cubic zirconia. If there is a laser inscription, we match it to any report you have. It does not matter where the piece came from, and there is no pressure to buy or sell. If the stone needs a full independent lab report to settle its value or origin, we will explain that and help you arrange it.