Does Moissanite Pass a Diamond Test?

Yes — moissanite passes a standard diamond tester, and that surprises a lot of people. It's not a trick or a defect; it's basic physics. Here's what's actually happening and which test genuinely tells the two stones apart.

The classic handheld 'diamond tester' works by measuring thermal conductivity — how fast a stone moves heat. Diamonds conduct heat exceptionally well, and so does moissanite. Because the two are so close on that one property, moissanite reads as 'diamond' on a basic thermal tester. Glass and cubic zirconia fail this test; moissanite passes it.

A dual moissanite/diamond tester adds a second measurement: electrical conductivity. Moissanite conducts electricity in a way diamond doesn't, so this tester correctly flags moissanite as moissanite. If a jeweler wants certainty, this is the tool they reach for.

Without any tester, the giveaway is fire: moissanite throws noticeably more rainbow flash, especially in bright light. Under magnification, its facet edges can also appear slightly 'doubled,' which a diamond's never do. On a hand across a room, though, neither is visible — which is rather the point.

No — it just means moissanite shares one property with diamond. It's still its own gemstone. Every Airwaves stone comes GRA certified as D-color moissanite, so you always have documentation of exactly what it is, tester or no tester.