How to Check the Authenticity of a Diamond

Understanding The Diamond Cut

Many people mistake the diamond cut for its shape. When they hear a about princess cut, emerald cut, brilliant cut, marquise or other similar things, they automatically imagine three’s nothing more to the cut than a certain shape. As a matter of fact, the cut grade is a completely different concept. It refers to the sizes of the facets, the proportions and angles made by the facets of a stone. This has nothing to do with the shape. Even more, each specific shape has its own set of measurements that are considered optimal.

The cut has a major influence on the market price of a diamond. This is easy to understand if you think that improper angles and a wrong depth in going to interfere with the path of the light through the crystal, preventing it from going out through the top of the diamond. This is pure optics, and this is how you have to think about it. A slight deviation from the good angle may determine the light to reflect under a different angle. Even a tiny difference can become as big as to prevent the light to go out through the crown. Each and every facet and angle matters, because their size, shape and positioning determines a unique path the light follows through the stone. A tiny change can prevent a big amount of this light to come out through the top of the diamond, thus making it appear dull and dark. The more light is lost in these reflections and refractions, the less brilliance a diamond is going to have. As brilliance is one of the greatest assets of these gems, it’s easy to see why their cut needs to be perfect.

Diamond cutters have a very difficult decision to make whenever they have a rough stone in front of them. Their objective is to save as much of the raw material as possible, so they tend to go for the maximum possible carat weight. However, sometimes this means they have to sacrifice the cut, as the raw crystal isn’t tall enough to allow for the optimal depth of the polished gem. The other option is to sacrifice a part of the carat weight, and go for the perfect cut. As both parameters have a direct influence on the value of the diamond, the struggle is fierce and the decision hard to take. Sometimes it’s better to obtain a smaller, but better diamond than a larger one with a fair or poor cut. Some diamond cutters are true artists, artisans who can close their eyes and picture the perfect shape inside the raw crystal. With the help of the International Colored Gemstone Association we were able to find out even more about these issues!

The cut is a reflection of how well a gemstone is able to transmit the light. As it is very complex and extremely difficult to analyze, the cut is usually measured by experts and assigned one of the five grades on GIAs diamond cut scale. These five grades and Excellent, Very Good, Good, Fair, and Poor. As the top of the scale may be out of your budget limits, you should seek to determine how low you can go without compromising on the symmetry and on the brilliance of your diamond.

Ideally, you should try to stay in the Good range or above, as that’s where the beautiful gems are. It’s better to go down one or two grades on color or clarity than to compromise on the cut. Clarity is one of the most versatile parameters, as there are gems with fairly large inclusions that appear flawless when observed from the top. The location of these inclusions inside the crystal can make a huge difference. This is why you can try to find a lower clarity grade gem, while sticking to your desired cut grade.

A good cut is the guarantee of sparkling beauty and brilliance. This is what makes these gemstones so appreciated and valued all over the world. They are symbols of love and wealth, so they can only be perfect. As the cut grade is the measure of this perfection, it should be as good as possible. You need to find the right balance between the cut grade, the clarity and the color, and then pick the biggest diamond that fits into your budget. You should never start your search from the carat weight, as you may not be able to find anything suitable. On the contrary, if you do your homework well, and if you’re willing to compare and study lots of stones, you may end up with a diamond larger than you’ve wanted, with not compromise on its cut grade. For specific parameters of the diamond cut click here! Such situations aren’t frequent, but they aren’t impossible, either. If needed, ask an expert to give you advice and to guide you along the shopping process. This could be more useful than you can imagine.

Ways to see whether the diamond is real or fake!

  • One of the easiest and simplest tricks is to fog the diamond. Just keep the diamond in front of your mouth and fog it just like a mirror. If it clears instantly, then it is a real diamond, and if it takes some time to clear, it is possibly a fake diamond.
  • Check the diamond through a magnifying glass called as the loupe. If it is a fake diamond, then you will find that the stone is entirely perfect. The real diamond will have imperfections that will be visible to you through the loupe.


  • The sandpaper test is another test that can help you to see whether the stone is real diamond or a fake one. If you rub the sandpaper on the real diamond, there will be no scratches on it because the diamond is the hardest material on earth. However, the sandpaper will scratch the surface of a fake diamond.
  • Light reflection is another test that can be done to check the authenticity of the diamond. If the inside of the stone reflects gray and white color when you hold it in sunlight and reflects rainbow colors on any other surface, then that is a real diamond. A fake diamond will reflect rainbow colors from inside.

If you keep a real diamond on a newspaper, you won’t be able to see any black color through the stone, but a fake diamond will show you the black letters of a newspaper.

  • As all these tests are just layman’s tests, you can further decide the authenticity of the stone by using two more devices. Diamond testers will help you to measure the thermal conductivity, and electrical testers will assist you in checking the electrical conductivity of the stone so that you will able to know whether your diamond is real or not.