The Surprising Answer
Yes, moissanite will often pass basic thermal diamond testers, which measure heat conductivity. This happens because moissanite conducts heat similarly to diamond—but this doesn't mean moissanite is fake or trying to deceive anyone.
Understanding Diamond Testers
Traditional diamond testers work by measuring thermal conductivity. Diamonds conduct heat exceptionally well, whilst most diamond simulants (like cubic zirconia) do not. These testers were designed before moissanite became widely available in jewellery.
Why Moissanite Tests as Diamond
Moissanite's thermal conductivity is nearly identical to diamond's, causing thermal testers to register a positive result. This is simply a property of moissanite's silicon carbide structure—not an attempt to imitate diamonds.
Electrical Conductivity: The Key Difference
Modern diamond testers measure both thermal AND electrical conductivity. Diamonds do not conduct electricity, whilst moissanite does. Advanced testers use this distinction to differentiate between the two stones accurately.
Professional Identification Methods
Jewellers and gemologists can easily distinguish moissanite from diamond using:
- Dual thermal/electrical testers
- Loupe examination (moissanite shows double refraction)
- Specific gravity testing
- Spectroscope analysis
- Refractive index measurement
Why This Matters (And Why It Doesn't)
If you're buying moissanite, you're making an informed choice for a brilliant, durable, ethical gemstone at exceptional value. Moissanite isn't pretending to be diamond—it's a superior alternative with its own distinct advantages.
The diamond tester question only matters if someone is trying to misrepresent a stone. Reputable jewellers clearly label moissanite and provide certification.
Moissanite Certification
Quality moissanite comes with certificates verifying:
- Gemstone type (moissanite)
- Carat weight
- Colour grade
- Cut quality
- Clarity characteristics
This documentation ensures transparency and authenticity.
The Ethical Perspective
Moissanite's ability to pass basic diamond testers doesn't diminish its value or integrity. You're choosing moissanite for its brilliance, durability, sustainability, and price—not because you're trying to fool anyone into thinking it's a diamond.
What to Tell People
When someone asks about your stunning ring, you can proudly say it's moissanite—a gemstone that sparkles more brilliantly than diamond, costs a fraction of the price, and aligns with your values. That's something to celebrate, not hide.