You might have heard that there are a lot of ways to tell whether a diamond is real or fake. The problem is that most of these methods are not 100% reliable. Using a diamond tester, however, is one of the surest and fastest ways to check if you have an original diamond.
What Are Diamond Testers?
A diamond tester is a portable device that you can put in your pocket. The tester has a small, needle-like tip that needs to be placed on the stone tested. If the diamond is real, the device indicates that on its display or with a sound signal.
How Diamond Testers Work
Diamond testers’ principle of operation is based on the fact that different gemstones conduct heat differently. Heat will pass through a diamond in a different way than it would through cubic zirconia or glass.
A diamond tester will detect the rate at which heat moves through the stone and will tell you whether it is a real diamond.
There are also testers that use electrical conductivity to test stones – they are based on a similar principle, but they use electricity instead of heat.
What Are Diamond Testers Used For?
Diamond testers are used by jewelers all the time to check the authenticity of diamonds.
If you bring in your diamond with the intention to sell it or exchange it for another one, the jeweler will want to make sure your stone is real as this is not always obvious.
Before repairing a piece of jewelry, it is also critical for a jeweler to know what the stone in the setting is since different gemstones tolerate heat, pressure and stress differently.
As a customer, it is a good idea to make the person who repaired your diamond jewelry test the stones in front of you when you are receiving them.
And if you are not sure that the gemstone you have is a real diamond, you can always go to a jewelry store and ask to have your stone tested.
How Reliable Are Diamond Testers?
Diamond testers are one of the most accurate tools to check a diamond for authenticity.
However, you should know that testers that rely on thermal conductivity can mistake a moissanite for a diamond because these two stones are very similar in the way they conduct heat.
This problem is solved by using a device that uses electrical conductivity to test stones – diamonds and moissanites conduct electricity differently.
What Makes a Good Diamond Tester?
If you’ve decided that you want to buy a diamond tester, there are several things you should be looking for.
First, make sure that the device uses electrical conductivity in order to tell a diamond from a moissanite. The latest models available on the market combine heat/electricity testing for greater accuracy.
Another good feature is having a metal detector that signals if you accidentally touch part of the metal setting instead of the stone.
If your tester doesn’t recognize metal, it can indicate that you are holding a real diamond when you unknowingly touch the setting, even if the diamond itself is fake.
Where to Buy Real Diamond Jewelry?
For genuine diamond jewelry, we highly recommend James Allen (read our review) because it shows real photos and videos for each diamond so you can take a 360-degree look at any stone before buying it.
For colored diamonds, we recommend Leibish & Co., which specializes in fancy color diamonds (use code JewelryNotes200 at checkout to get a 5% discount).
Also read our Diamond Buying Guide and check out our selection of eye-clean diamonds that we've vetted for quality.