Identifying Real vs. Fake Diamonds

Imagine this, you get home from making a large purchase of investing in some diamond jewelry, only to discover you’ve been duped for a look alike. This is a problem that many people have unfortunately faced both knowingly and unknowingly. Below we have listed some tips and tricks to identifying whether your diamonds are the real deal or a look alike.

Fog Test

Hold your diamond with two fingers and lightly breath on it. If it is real, a light amount of fog will form on the diamond due to the fact that there is moisture and heat in your breath. If it takes more than a few seconds for the fog to disappear you have a fake diamond if it disappears right away; the diamond is authentic.

Water Test

Find an average sized drinking glass and fill it up ¾’s of the way. Carefully drop your diamond into the glass. If the gemstone then sinks, it’s the real deal. If it floats on the surface of the water you, unfortunately, have a fake on your hands. Authentic diamonds have a very high-density rate which is easy to identify using this water test.

Assess the Setting

For diamonds that have already been placed in a setting, examine the mount in use. Real diamonds are usually set in high-quality jewelry such as gold or platinum. Check the markings on the interior of the ring band or jewelry for markings such as 10K or 18K to identify the gold being used. If it says PT or the abbreviation Plat, this is in reference to platinum material. If you see a “C.Z.” engraving on the stone it is cubic zirconia and unfortunately not a real diamond.

Shatter Test



Authentic diamonds are very strong and do not react to high heat. To use a shatter test, use a drinking glass and fill with cold water. Use fire retardant gloves or plyers to hold the stone, then use a lighter to heat the gemstone for up to 40 seconds then place in water. If the stone then shatters it is mixed with weaker components and is not a true diamond. A real diamond will have no reaction to this test. Due to the fact that diamonds are some of the most durable materials known to man, it will be unaffected by exposed heat.

Test at Home with Light Refraction and Reflection

 Expert Tactics to Examine Diamond

Using a Loupe

Visit your local diamond expert to perform this test. The examiner will use a professional tool called a loupe which magnifies the makeup of gemstones. Under the loupe, the examiner will be able to identify small inclusions which assure that the diamond is real.

Using a “Diamond Tester”

A diamond expert or gemologist often have professional grade thermal conductivity probes that determine the overall thermal conductivity of different stones. Due to the fact that diamonds are great heat conductors, authentic diamonds will release heat after being warmed. If the rate of heat dispersion is slower, the diamond can be identified as fake. You can also get your hands on a home use diamond tester by visiting sites like Amazon or other online retailers.

Electric Conductivity

The use of electric conductivity is also an effective way to identify a real or fake diamond. This test is better if performed by a gemologist. Seeing as though diamonds are one of the most notable gemstones to conduct electricity, a true diamond expert will be able to confirm this for you.

Real Diamond vs. Moissanite

Use a Microscope

To conduct this test you must have a microscope with a zoom capability of 1200x magnification. A jeweler usually has access to this equipment, which magnifies the impurities and inclusions of the stone. This examination can determine whether it is real or a moissanite.

X-Ray Examination

This examination requires sending your gemstones off to a professional examiner for testing. The gemologist will use high-grade x-ray machines to tell if the stone has a radiolucent molecular structure vs. a radiopaque molecular structure. Authentic diamonds will result in a radiolucent structure as opposed to fakes.

Can I use the “Scratch Test”?

This method is not advised seeing as though stones like cubic zirconias and moissanite have a high durability rate just like diamonds which can lead to confusion and false results. We suggest using other methods of testing to ensure authenticity. 

Ways to Identify a Synthetic Diamond vs. A Substitute

Diamond vs. Cubic Zirconia

Because of their similar appearance, it can be very easy to mistake cubic zirconia for a diamond. Using the sparkle test, however, you will be able to examine the amount of sparkle which will give you the answers you need. Cubic Zirconias also give off an orange tinge in the light which separates them from their look-alike authentic diamonds. They also tend to weigh more in comparison to a real diamond.

Diamond vs. White Sapphire

Because some sapphires come in a white hue, as well as blues, etc; they can often be mistaken for a real diamond. White or clear looking sapphires, however, do not give off the same sparkle and contract of light vs.dark that diamonds do. Blurred colors or low-grade sparkle is a key factor in determining a sapphire versus a diamond.

Diamond vs. Moissanite

Known as one of the closest replicas to a real diamond, synthetic moissanite is a substitute that is best differentiated by a diamond professional. However, an electric conductivity test can ultimately determine if your gemstone is moissanite vs. an authentic diamond.

Diamond vs. White Topaz

Examining the overall appearance of white topaz is the best way to differentiate it between a diamond. Topaz has a softer exterior in comparison to a diamond and can be easily nicked or scratched. You can also use a magnifying glass to see if there are any scratches on the gemstone. If there are, it is a topaz seeing as though diamonds will not have scratches because of their highly durable makeup.