Judging if a Diamond is Real or Fake: A Few Quick Tips


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It goes without saying that diamonds are expensive and always in high demand.  There are numerous kinds of fake or faux diamonds, including glass, plastic, simulant and synthetic stones.  While expert diamond and gemstone requires scientific tests and much experience, the following offers a few quick tips for judging if a diamond is the real thing.

A simulant diamond resembles a diamond but is something else, including glass and other stone

A synthetic gemstone is a diamond but man made in a laboratory, instead of in nature.  It has the exact same chemical and crystal makeup.   Synthetic stones can look great, sometimes better and bigger than the naturally flawed, natural diamond, and can have value, but is worth less than the natural counterpart.  There is higher demand from the public for natural.

Tips in no particular order.  No single test proves it’s diamond but provides useful evidence.:

1) Diamond (natural or synthetic) is the hardest natural material on earth.  It will not by scratched by an other substance.  It easily scratches glass and other stones.  A steel knife won’t cut it.  However, there are other very hard, if not as hard, stones including rubies.

2) Diamonds are cold to the touch.  They don’t heat up.

3) Try reading through the stone.  Due to the way diamonds manipulate the light, you can’t read a newspaper or other text through a diamond.  If you can read through it, it’s not a diamond and likely glass.

4) Diamonds stay dry.  Fog it up with your breath.  The fog will disappear right away on a diamond.

5) Sharp edges and corners.   As diamonds are so hard, they don’t wear out.  If the corners and cuts on your diamond ring are rounded, it’s not a diamond.

6) Look inside for flaws and inclusions.  Natural diamonds are almost never perfect, but can have inside flaws, and inclusions.  If it’s perfect, it may be synthetic diamond or glass.  There are natural diamonds without flaws, but they are extremely rare and EXTREMELY expensive.  As in only the super rich could afford one.

7) If the stone has air bubbles, it’s glass.

8) Is the sales price consistent with it being a real diamond?  Use common sense.  Someone isn’t going to sell you a natural diamond for a fraction of the price.

9) Check the mount.   In particular for modern jewelry, a quality diamond will be on a ring or earring made of precious metal, like high grade gold, silver or platinum.  If the ring is made of brass, aluminum or steel, it probably isn’t holding a diamond.  The type and quality of of the precious metal is usually stamped into the metal and can be located somewhere on the jewelry.

10) Electronic diamond testers.  Most gem testing equipment is pricey, but there are inexpensive and handheld diamond testers.  They can quickly tell if you if a diamond is genuine or simulant.  The catch is it can’t tell the difference between synthetic and natural diamonds– as they are both diamonds.  Luckily, synthetic diamonds for jewelry is a recent phenomenon so if you’re certain the diamond ring is from 1850, then it’s natural not synthetic.  Also, and as already noted, synthetic diamonds can be perfect whereas natural diamonds will usually have inner flaws.  You can find diamond testers for sale at eBay, amazon and similar places.

11) Ask for outside expert opinion.  Purchase a diamond that has already been certified and graded by reputable company like GIA.  You can also submit it for a certificate.  A local jewelry store may be of help.  The Jeweler may charge you.