When it comes to diamonds, trust is everything. With so many simulants (moissanite, cubic zirconia, and lab-created lookalikes) on the market, it’s natural to wonder if your stone is the real deal. While nothing replaces professional testing and certification, there are several at-home methods that can give you clues—though some are far more reliable than others.

The Fog Test

Breathe onto your diamond as if you’re fogging a mirror. Real diamonds disperse heat quickly, so the fog should disappear almost instantly. If the fog lingers, the stone may not be genuine. Still, this method isn’t foolproof, especially in humid environments.

The Water Test

Drop the stone into a glass of water. A real diamond, with its high density, will sink to the bottom. Many imitations, like cubic zirconia, will float or settle slowly. This test is simple, but it can be inconclusive—some simulants have similar density to diamonds.

Brilliance and Sparkle Test

Under light, diamonds reflect in two ways: white light (brilliance) and rainbow flashes (fire). A true diamond will balance both beautifully, while simulants often show excessive rainbow sparkle or look dull in comparison. Comparing side by side with a known diamond is helpful here.

Myths to Avoid

• The Scratch Test: Scratching glass with a stone doesn’t prove it’s a diamond. Many materials can scratch glass, and you risk damaging both your stone and the surface.

• The Flame Test: Holding a stone over a flame can fracture it—never attempt this at home.

The Expert’s Word

At Diamond Tales, we stress that DIY tests are only a starting point. The only way to be absolutely certain is with professional testing and certification from trusted institutions like the Gemological Institute of America (GIA). Your jeweler can also use specialized tools, like a diamond tester, to confirm authenticity without risk.

Diamonds are investments meant to last generations. While it’s fun to try at-home tricks, nothing replaces expert verification for peace of mind.