How Are Lab Diamonds Tested?
A diamond tester is a handheld device used to identify whether a stone is a diamond. These tools work by measuring either thermal conductivity or electrical conductivity of a gemstone.
- Thermal conductivity testers: Diamonds have high thermal conductivity, meaning they transfer heat quickly. When the tester's probe touches the stone, it measures how much heat dissipates. If the rate matches that of a diamond, the tester indicates a positive result. These are the most common types of testers, and they rely on the fact that diamonds are excellent conductors of heat.
- Electrical conductivity testers: Some testers include an additional setting to detect electrical conductivity. This feature is essential for distinguishing diamonds from moissanite and is often used for that purpose, as both moissanite and diamonds have similar thermal properties but moissanite conducts electricity while diamonds generally do not.
Do Lab Grown Diamonds Pass a Diamond Tester?
Lab-grown diamonds are identical to natural diamonds and therefore do pass a diamond tester. Since these gemstones are chemically, physically, and optically the same as their natural counterparts, a thermal conductivity test will confirm them as genuine diamonds.
However, the type of tester used, and the testing method, can impact the results:
- Thermal testers: Lab-grown diamonds pass, as their thermal properties match those of natural diamonds.
- Electrical conductivity testers: These devices can sometimes detect inclusions or differences in trace elements within lab-grown diamonds, potentially leading to inconclusive results.
While diamond testers are a helpful tool, advanced testing methods—such as spectroscopy or grading reports from certified gemological laboratories—are the most reliable for verifying lab-grown diamonds.
Do Lab Grown Diamonds Test as Moissanite?
No, lab-grown diamonds generally do not test as moissanite. Moissanite and diamonds have different electrical and optical properties, allowing advanced diamond testers to distinguish between the two.
- Electrical conductivity: Moissanite conducts electricity, whereas most diamonds, including lab-grown ones, do not. High-quality testers with electrical conductivity settings can clearly differentiate between lab-grown diamonds and moissanite.
- Thermal properties: Although both diamonds and moissanite conduct heat efficiently, moissanite's unique crystalline structure gives it distinct refractive and conductivity characteristics, which testers can identify.
For the most accurate verification, confirm the gemstone with its certification from a recognized gemological institute such as GIA or IGI.
