12 Ways to Determine if a Diamond is Real

Whether you're buying that perfect gift for a special person in your life, or if you just want to know if your own diamond is the real thing; people have a lot of questions about how to tell the real thing from a fake. Obviously, working with a reputable jeweler you trust who can test the diamond without damaging the stone is always best, but here are a few helpful tips so you can learn to spot the real thing like a pro. 1. Ask to See the Paperwork - Most diamonds will have some sort of certificate from a grading authority such as GIA, EGL, AGS, HRD, etc and/or an appraisal from an independent appraiser who is affiliated with the GIA, American Society of Appraisers or other accredited professional organization.  Certificates are issued on diamonds that have been certified, and it gives all the specific details about the stone, its weight, measurements, origin, etc. A certificate is not the same as an appraisal, however.  An appraisal is used to determine the market value of a stone or fine piece of jewelry at the time it is appraised. 2. Check the Setting - Real diamonds are normally set in yellow gold, white gold or platinum settings. Check the stamps inside the setting. If you see: 10K, 14K, 18K, 585, 750, 900, 950, PT, or Plat, the setting is gold or platinum, that is a good indicator that the stone set in it may be a diamond. However, if you see the letters GF, RGP, or GP, these indicate the setting is gold plated or gold filled. If you see: sterling, 925, 9.25 or .925, the setting is sterling silver. If the setting is not gold or platinum, the stone is most likely not a diamond.  However, several popular jewelry designers, such as David Yurman, Judith Jack, John Hardy and others are setting semi-precious stones and diamonds in sterling silver and/or gold settings so while this is an indicator, the stamp in the setting is not a definitive way to determine if the stones in the setting are or are not real diamonds.  Likewise, if you see a stamp that says C.Z., this indicates the center stone is a cubic zirconia (regardless of what metal the setting is), although not all settings with cubic zirconias are marked that way. 3. Use a Jeweler's Loop - Mined diamonds as well as other natural stones will usually have small imperfections visible in the stone when viewed under a jeweler’s loop. These imperfections, known as “inclusions,” are natural flaws that occur during the formation of the stone. A real diamond will, more often than not, have some form of visible inclusions present in the stone. A complete lack of inclusions indicates one of two things. Either the stone is a very high quality flawless or internally flawless diamond, (which would be a very expensive stone), or it is not a diamond at all. Cubic zirconias, moissanites and other synthetic lab-grown diamonds will usually not have any imperfections. 4. Look Through the Stone - Diamonds have a high refractive index, meaning they sharply bend light that passes through them. This is why diamonds sparkle like most nothing else. Glass, quartz and other simulations also bend light, but they have a lower refractive index. This means that even when they’ve been nicely cut, they sparkle less than a real diamond because they don’t bend light as well. If the stone is in a setting, look into it from the top of the mounting. You should not be able to see the bottom point of a diamond when looking directly into it from the top. If you have a loose stone, turn it upside down and place it flat side down on a piece of newspaper. If you can read the print through the stone, or even if you can see distorted black smudges, it probably isn't a diamond. Another thing you can do is to draw a line on a piece of paper. When you place the stone on the line, you will not be able to see the line through the stone at all if it is a diamond. 5. Observe the Reflections of the Stone - A real diamond's reflection will usually manifest in various shades of gray. If you see rainbow reflections, it may either be a lower-quality diamond, or it may not be a diamond at all. 6. View the Stone Under A Microscope - Hold the stone with tweezers under a microscope upside down with the point facing up. As you tilt the stone under the lens, if you see an orange flash, it is probably not a diamond. 7. A Diamond Can Be X-Rayed -  A real diamond is radiolucent but crystals or cubic zirconium exhibit radiopaque signs. Diamonds don't come up on x-rays. 8. Test Your Diamond with a Thermal Probe - This device will show if the diamond is genuine, if the diamond is real it will give a signal and if it is fake there will be no signal from the device. 9. Have Your Diamond Evaluated - A reputable diamond dealer such as Diamond Doctor Wholesale Diamonds and Fine Jewelry can give you expert advise on your diamond's quality or authenticity. 10. U.V. Your Diamond - True diamonds have fluorescence which are visible under ultra violet light. Most fake diamonds don't have fluorescence.   11. Weighing The Stone - Weighing a cubic zirconium or c.z. will reveal that it weighs 55% more than a real diamond of it's comparable size. 12. Breathing On A Diamond - If you breath on the stone as you would a mirror and the fog stays on the surface of the stone for some seconds then it may not be a true diamond. More testing should still be performed.