How To Tell If You're Purchasing A Real Diamond

Image by VideoMagus via Flickr
 If you’re considering buying a diamond, you know it’s a hefty investment, and you do not want to be caught out buying a fake. Sadly, there are underhanded sellers out there who will try to sell you a fake diamond. To protect yourself, there are a few ways to tell if a stone is real before you purchase it.

 Before You Buy the Diamond
  1.       Certification
Make sure you ask the jeweller for a certificate for the diamond. Independent, reputable jewellers will be able to give you a diamond report or certificate from a regarded laboratory. This proves the stone’s authenticity. Make sure you do receive the certificate from the actual lab, and not just a certificate the jeweller has created.

      2.  Laser Inscription 
You should find out if the diamond has been laser inscribed with an ID number or any other kind of identifying mark. The inscribed ID number will correspond with the stone’s certification, validating its authenticity. The marks are usually inscribed on the diamond at the lab that graded it, to ensure the diamond is linked to its original paperwork.
There are also a number of DIY tests you can do yourself to find out if the stone is the real deal.
DIY Tests for Loose Stones

1          1.  The Dot Test
Take a ballpoint pen and piece of white paper and draw a small dot on the paper. Flip your diamond upside down and centre it over the dot. If the diamond is real, it will break up the reflection, and you shouldn’t be able to see the dot through the stone. A fake diamond will appear like a piece of glass and you will see the dot beneath it.

2           2.  The Precision Test
You can use a precision scale to weigh your diamond and determine it if it real. Typically, a 1 carat diamond will weight 200 milligrams, where as a Cubic Zirconia of the same size will weigh double that amount.
DIY Tests for Mounted Stones
These tests can be used on either loose or mounted stones.

1           1. Scuffing or Scratching
Never purposely scuff a stone. But, if your stone is vintage, examine it carefully for scratches and scuffs. A Cubic Zirconia stone will show marring on the surface, whereas a real diamond won’t.

2           2.  The Breath Test
A natural diamond is an excellent conductor of heat. Breath on the table of the stone, and an authentic stone will clear almost instantly.

3           3. Magnification
You can also use a jeweller’s loupe or a microscope to determine if your diamond is real. Look at the stone under magnification and through one of the star or bezel facets on the crown of the diamond. If you notice what seems like double lines on the facets, the stone may well a Masonite.  You can also use the magnifier to look at the stone’s girdle. A real diamond will have a grainy, somewhat frosted appearance.

Overall, the best way to figure out if you are purchasing a real diamond is to have a professional look at it and appraise the stone.


  1. I had to buy 1 carat loose diamond for my ring. After trying these methods, I have found a good quality diamond for myself. Really these steps have helped me a lot.