Online diamond testers, such as handheld thermal/electrical probes (Presidium, GemOro) or app-based screeners (Gemetrix), quickly differentiate diamonds from simulants like cubic zirconia (CZ). While they can distinguish moissanite, professional laboratory verification (e.g., GIA) is required to separate natural from lab-grown diamonds.
Common Online Diamond Testers
- Handheld Probes: Detect thermal/electrical conductivity, separating diamonds from simulants like CZ and, in some cases, moissanite.
- Presidium Diamond Mate-C : A popular portable tester for diamonds and moissanite.
- Gemoro Pro D-3: Features an aluminum testing plate for enhanced accuracy.
- GemTrue Combo Tester : Frequently available online for testing diamonds and moissanite.
- Smartphone Apps/Screeners:
- Gemetrix App : Used in conjunction with UV lighting devices to identify fluorescence and potential lab-grown stones.
- DiamondEye : A mobile app intended to verify diamond authenticity.
- Professional Devices:
- GIA iD100 : High-sensitivity device that uses spectroscopy to detect lab-grown diamonds and treatments.
- Ogitech DiaTrue : A scanner that can test large batches of stones for screeners.
Key Considerations
- Limitations: While most testers accurately identify CZ, some, especially older models, struggle to distinguish between natural and synthetic (lab-grown) diamonds, or between diamond and moissanite.
- Best Use: Use them for screening jewelry at home or in estate jewelry, but rely on third-party certifications (e.g., GIA) for high-value authentication.
- Price Points: Basic models are available for under $100, while more advanced, specialized, and reliable machines (like the GIA iD100) are significantly more expensive.