If you are considering moissanite jewelry, the most common question is: “Does moissanite pass a diamond tester?” The short answer is “yes“—most moissanite can pass a standard diamond tester. But the real explanation is more nuanced than that.
The Science: Why Moissanite Can Pass a Diamond Tester
Traditional diamond testers do not actually “see” a diamond. Instead, they measure thermal conductivity—how quickly a stone transfers heat. Diamonds are excellent heat conductors.
Moissanite is also an exceptional heat conductor. Because it is made of Silicon Carbide, its ability to conduct heat is remarkably similar to a natural diamond. When a standard tester pen touches a VVS Moissanite stone, the heat signature closely matches that of a diamond, triggering the “Diamond” alert. This test confirms the stone isn’t glass or Cubic Zirconia (CZ), but it cannot distinguish between a Moissanite and a natural diamond.
Moissanite is actually as bright as diamond, with a refractive index of 2.65 (compared to 2.42 for diamond). It produces 2.5x more “fire” or rainbow sparkle. Additionally, moissanite is nearly as hard as diamond, ranking 9.25 on the Mohs scale, second only to natural diamond.
Key Factors in Testing:
- Thermal Sensors: Standard pens (like the Diamond Selector II) will almost always identify Moissanite as a diamond.
- Electrical Conductivity: This is the key difference. Moissanite is semiconductive, whereas most natural diamonds are insulators.
- The Multi-Tester: Advanced 2026 equipment, known as “Multi-Testers,” measures both heat and electricity. These can distinguish between the two gems.
Moissanite vs. Natural Diamond: A Technical Comparison
To understand why Moissanite is the ultimate “diamond alternative,” look at the physical specs that allow it to perform at an elite level.
| Feature | VVS Moissanite | Natural Diamond |
| Passes Thermal Tester | Yes | Yes |
| Refractive Index | 2.65 – 2.69 (More Sparkle) | 2.42 |
| Hardness (Mohs) | 9.25 | 10 |
| Chemical Composition | Silicon Carbide (SiC) | Carbon (C) |
| Brilliance / Fire | Higher Rainbow Fire | More White Sparkle |
| Valid Certificate | GRA | GIA/IGI |
| Source | Lab-Grown | Land Mining |
| Price | Much More Affordable | Significantly Higher |
| Identifiable by Experts | Yes | Yes |
The “Double Refraction” Factor
In 2026, experts don’t just use testers; they use the “naked eye” test. Moissanite is doubly refractive. This means when light enters the stone, it splits into two rays.
For the wearer, this results in the “Disco Ball Effect”—a higher level of rainbow fire and brilliance than a diamond. In an “iced-out” Cuban link chain, this extra fire is exactly what gives the piece its high-end “hit” under club or sunlight.
Trusted Buying: GRA Certification
Because Moissanite can pass a tester, it is vital to buy from a Trusted Seller who provides GRA (Gemological Research Academy) Certification.
Authenticity: Every stone should have a unique serial number laser-inscribed on the girdle.
Grading: A certificate ensures you are getting D-Color (Colorless) and VVS1 Clarity (Very Very Slightly Included).
As a trusted seller, we guarantee that every Kermis Luxury jewelry piece will pass a professional thermal diamond tester and that each piece will include a standard GRA certificate.
Frequently Asked Questions
1. Does moissanite always pass a diamond tester?
Most genuine VVS moissanite passes a standard thermal tester, but some stones may not pass the tester due to the type of tester, stone size, and setting.
2. Can fake moissanite pass a diamond tester?
No. Many fake stones marketed as moissanite are CZ or glass and will fail thermal testing.
3. Does Moissanite lose its sparkle or turn cloudy?
No. Unlike Cubic Zirconia (CZ), Moissanite is a stable gemstone with a 9.25 Mohs hardness. It will never scratch, cloud, or fade. Its brilliance is permanent.
4. Are Kermis Luxury stones GRA Certified?
Yes. Every stone over 0.5 carat at Kermis Luxury comes with a GRA (Gemological Research Academy) certificate. This verifies the stone’s D-color, VVS1 clarity, and unique serial number.
5. Is moissanite better than cubic zirconia (CZ)?
Yes. Moissanite is harder, more durable, and much more brilliant than cubic zirconia.