How to spot a real diamond

Posted: August 15th, 2014 | Author: | Filed under: Uncategorized | Tags: , , , | No Comments » -->
brilliant cut diamond

Brilliant cut diamond, shot by Sparkle Photography


Here at sparkle photography we shoot a wide variety of  jewellery, watches and diamonds. From fun costume jewellery to luxury one off pieces. We endeavour to make every single item look as beautiful as possible, however nothing shoots quite like a well cut natural diamond!

With the ever increasing popularity of vintage fairs, flea markets and online auctions, second hand jewellery, vintage jewellery and diamonds are big business. So how can you tell if you are getting the bargain of the century or being fobbed off with a bit of old glass?

Here are our top tips on how to spot a real diamond on the fly.

Testing a mounted diamond


. The fog test.

Simply breathe on the stone to fog it up as you would a mirror. If the stone stays fogged up for more than a second or so, it is likely not a real diamond. A real diamond will disperse the heat from your breath almost instantaneously and will not fog up easily.

2 . Check the setting.

Real diamonds are not likely to be set in cheap metals. Look for hallmarks indicating gold, silver or platinum ( 375,585,750,800,925,950 are all good).  Also look for obvious stamps that might indicate the type of stone , such as dia (diamond) , cz (cubic zirconia) etc, although these kind of stamps are rare.

3. Inspect the stone closely.

If you can get your hands on a jewellers loupe or powerful magnifying glass, take a close look at the stone. Look for inclusions and imperfections. Synthetic diamonds or cubic zirconia are usually made flawless. If it is perfect then it is unlikely to be a real diamond. Cubic zirconia can also have a waxy appearance, where as diamond should appear clear.  This step is highly recommended as some lab grown diamonds can pass the first two tests!!

Testing a loose diamond


1. Look at the stones refractivity.

A real diamond will sharply bend or refract the light passing through it, resulting in a bright sparkling appearance. A quartz or glass stone for example, will simply not look as sparkly or bright in the same light. This is due to them  having a lower refractive index than diamond. This is an inherent quality of the stone and is hard to replicate in a lesser stone, even with an expert cut!

Here are a couple of ways to do it;

The newspaper method:

Turn the stone upside down and place it on a sheet of newspaper. If you can read the print through the stone, or even distorted words or dark smudges, then it probably isn’t a real diamond. A real diamond would refract the light so sharply that you wouldn’t be able to see the print through the stone.

 The dot test:   

Draw a small dot on a piece of plain white paper and place the stone upside down over the center of the dot. Look directly down on the stone. If you can see a circular reflection in the stone then it is unlikely to be a diamond. You shouldn’t be able to see the dot through a real diamond.

2. Observe the reflections.  

The reflections in a real diamond usually appear in various shades of gray. Look down through the top of the diamond, if you see rainbow or multi coloured reflections, then this could indicate that you have a low quality or fake diamond. Remember it should also have an intense bright sparkle.

3. The weight test.

If you have access to a sensitive digital scale, compare the weight against a certified diamond. Cubic zirconia can weigh upto 50% more than a diamond of a similar size.

Professional appraisal

Although this guide may be handy when in a pinch, the only sure way to tell if your diamond is the real deal, is to have it professionally appraised by a member of the Institute Of Registered Valuers.

Click here to find local registered valuers

Happy hunting!



Photography for the Jewellery Industry

Sparkle Photography has been established since 2005. Our team of professional photographers, video editors and image retouchers have the experience to make your products look their absolute best.

Find out more about the Sparkle photography studio on the about us page.

All types of Jewellery:

  • High end jewellery
  • Costume jewellery
  • Gold, silver, platinum
  • Diamonds and other precious gem stones
  • Watches
  • Necklaces, braclets and bangles
  • Plus any other type of jewellery

Contact Sparkle

Telephone: 05601 132 384

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