How to Use a Diamond Moissanite Tester

Use a diamond moissanite tester to check a ring.

Cubic zirconia and glass replicas of diamonds can sometimes be detected with the naked eye or a magnifying glass, but a stone needs to be tested for heat conductivity to verify whether it is a diamond or a replica. Moissanite, which is a synthetic diamond and gemstone substitute made from silicon carbide, conducts heat just as well as diamonds do. Unlike diamonds, moissanite also conducts electricity. Therefore, a diamond must also be tested for electrical conductivity to ascertain its authenticity. You can use a handheld combination diamond and moissanite tester to differentiate between cubic zirconia, moissanite and diamond.

Things You'll Need

• Jewelry cleaning cloth or denatured alcohol
• Lint-free cloth

Instructions

1. Clean the stone to be tested and the probe tip of your tester. Use a cleaning cloth or denatured alcohol with a cotton bud as necessary. Dry the stone and tip thoroughly with a lint-free cloth.

2. Place the gemstone to be tested on a metal plate if it is not set in a metal setting such as a ring or pendant frame. Most testers are supplied with a metal plate for this purpose.

3. Plug your tester power cord into a standard electrical outlet or insert batteries as necessary. Turn your tester on by turning its on-off knob or flicking its on-off switch.

4. Allow the tester to warm up until its light or other indicator shows that it is ready for use.

5. Hold the tester in your right hand and the plate or setting that holds the gemstone in your left hand. Press the probe tip of the tester firmly against the center of the stone so that the tip partially retracts into its housing if it is spring-loaded. Hold it against the surface of the stone for a second or two.

6. Check the indicator lights according to the markings next to each light or according to the information in your tester owner's manual. On some models, a particular light flashes and a tone sounds depending upon the composition of the stone. On other models, a single light changes color according to the type of stone you are testing.

7. Watch the indicator light or lights carefully for a few seconds after they initially light up. Some testers test for moissanite (electrical conduction) only after the first test for diamond versus other substitutes (heat conduction) is completed.

8. Retest the gem if you hear a change in any tone while you are removing the probe or if your results are unclear.

9. Clean the probe tip of your tester once again before you store it in a convenient place.