How Can You Tell if a Diamond is Real?

Maybe you inherited a diamond recently, or perhaps you are thinking of buying one for your own collection or for someone special in your life. Knowing how to tell a real diamond from a fake diamond is a valuable skill.

The best thing you can do is have a professional jeweler appraise the diamond, but that may not always be an option, especially if you do not know one who you can trust.

Plus, if you are shopping for a diamond, you can hardly bring a jeweler with you to every store to appraise every diamond you find.

Here are some tactics you can use to determine the worth and genuineness of a diamond. Most of these are very simple and fast, and you can perform them yourself at any time.

How You Can Tell if a Diamond is Realhow to tell a real diamond fake diamond

  • First, ask for a certificate if you are shopping. Whether you are at a brick-and-mortar jeweler shop or you are shopping online, you should be able to get one of these. When shopping online, it is critical, since you cannot perform any other tests. It is simply a form provided by an independent appraiser stating that the diamond is genuine.
  • Can you see through the diamond? Diamonds have a high index of refraction. All this means is that they bend light sharply. They shine and sparkle more than quartz or glass. If you can see through a diamond, it may actually be a piece of quartz or glass. If you cannot, the odds are better that the diamond is genuine.
  • Look for colorful hues in the reflections. These are not supposed to be there. The reflections from a diamond should be white or grey. Colorful hues generally indicate that some other mineral is present.
  • Turn the diamond upside down, and place it under a microscope, if you have the opportunity to do so. When the diamond is back-lit like this, look through the microscope and tilt the stone this way and that. If you notice a flash of orange along the facets, that may indicate that the piece is either cubic zirconia or that cubic zirconia has been used to fill fractures in the diamond.
  • Weigh your diamond. Not only does cubic zirconia leave telltale orange flashes in the facets, but it also weighs about 55% more than diamond. Unfortunately this method only works if you have a real diamond to use as a comparison. With a carat or gram scale, check the weight of the questionable diamond against one you have confirmed to be real, if you have one (of the same approximate size and shape). This is a pretty reliable method, though also one of the more inconvenient ones.
  • Get a diamond/moissanite tester. This is an electronic device which can actually detect (within a reasonable degree of accuracy) whether a diamond is likely a real one or a fake. You can take it with you while you are shopping and save yourself a lot of money in many cases. Many jewelers who are in the business of buying and selling diamonds use these to help them make smart purchases.
  • Consider the setting of the diamond. If you had a real diamond, would you set it in a cheap metal? Probably not, since that would decrease the overall value of the piece. If the jewel is set in a high quality of real gold or platinum, that is a good indication. If it is clearly set in cheap metal, it probably is not a real diamond.
  • Put it under a black light. This is not a perfect test, since the absence of a blue glow does not mean you are dealing with a fake, but if you do see a blue glow, that is a strong indication of a real diamond. Moissanite often displays a different color of tint under black light, like green, yellow or grey. Very high-quality diamonds sometimes display no glow at all, so that is why you cannot necessarily discount a diamond that does not display any luminosity.
  • Try using a heat probe. It takes half a minute to test a stone this way. Diamonds don’t take in heat quickly, and will stay relatively cool when tested.
  • Another test involves trying to fog the surface of the diamond. This is related to the heat test, but you can do it without a heat probe. Try breathing on the diamond to fog it up. If it is a real diamond, it will quickly disperse the heat, and with it, the moisture. If it stays foggy for even a couple of seconds, odds are it is not a real diamond. Like the weight test, this one works best if you can try it with a diamond you have confirmed to be real first, so you know what you should be looking for.
  • Look for small imperfections in the diamond using a loupe or microscope. Cubic zirconia will not have these imperfections, but a real diamond will. Note however that a genuine lab-grown diamond will also be missing the imperfections, so this is not a foolproof test.

One more suggestion you might hear is to X-ray the diamond. If the diamond does not show up on the X-ray, supposedly you can assume it is real. This appears to be a myth. Where it started we don’t know, but we do know that diamond miners in South Africa are X-rayed to see if they are smuggling diamonds out of the mines (in their digestive tracts).

Your best option for accuracy is to choose several of these methods to test a diamond, and not rely on any single one. A number of these tests can be performed while you are shopping in brick-and-mortar stores in person.

If you are purchasing online, you will need to ask for a certificate, since you cannot see, touch, or test the diamond yourself until you receive it.

Other tests can only be performed at home, but can be used as confirmations once you purchase a diamond or inherit one.