Can Moissanite Pass Diamond Pen Test? Real Test Results & Working Principle

Ordinary handheld diamond testers judge gem identity based on thermal conductivity. Diamonds have extremely high thermal conductivity; heat injected by the tester probe dissipates rapidly inside the stone, which will light up the "diamond indicator light" on the device. Most imitation stones (cubic zirconia, glass, resin) feature low thermal conductivity, heat accumulates at the contact point, and the tester only alarms as fake gemstone.

Silicon carbide (moissanite raw material) has thermal conductivity close to natural diamond, far higher than cubic zirconia.

Ordinary entry-level diamond pens (the mainstream style for personal testing and small jewelry shops): Nearly all moissanite stones will display diamond positive signals completely. Mid-range thermal testers with partial discrimination function: A few high-precision thermal pens will give weak prompt differences, but cannot 100% separate diamond and moissanite. Conclusion: A standard thermal diamond tester cannot distinguish natural diamond from moissanite effectively.

Moissanite is lab-created silicon carbide with matched thermal performance, which can easily pass basic thermal testing. Colorless cubic zirconia fails the test obviously, so the tester can only rule out CZ/glass fakes, but cannot identify moissanite imitations. Fraudsters often sell certified moissanite as loose diamonds or diamond jewelry, counting on buyers only checking gems with a simple diamond pen.

Diamond is an insulator while moissanite conducts weak current. Dual-function testers can detect the conductivity difference and identify moissanite accurately.

Match the stone engraved serial number with official GRA / IGI certificate database information for verification.

Diamond RI: 2.417; Moissanite RI: 2.65~2.69. This fixed numerical gap supports precise differentiation.

Moissanite shows obvious double refraction under a 10x magnifying glass, an optical trait that single-refraction natural diamonds do not possess.

For daily preliminary screening: Thermal diamond pens are only used to exclude counterfeits made of glass, resin and cubic zirconia. Never judge a gemstone to be natural diamond merely according to a positive test result. If you need accurate authenticity verification: Purchase a dual thermal & conductivity tester or send your jewelry to official gem certification organizations for inspection. When purchasing moissanite jewelry from merchants: Confirm the product material is clearly labeled and ask for complete supporting certification papers to safeguard your legitimate rights and interests.

Moissanite can successfully pass conventional thermal diamond testers thanks to its similar thermal conductivity to natural diamond. A diamond testing pen is merely a basic screening tool rather than authoritative identification equipment. Learning multi-angle gem identification skills helps consumers stay away from counterfeit risks and make safe jewelry purchases.