Getting to know whether a diamond is real or not is quite easy. Here are two simple ways to do this:
Do an x-ray examination.
Diamonds have a radiolucent molecular structure, which means that they don't appear in x-ray images. Glass, cubic zirconium and crystals all have slightly radiopaque qualities that make them show up clearly on an x-ray.
If you want to get your diamond x-ray tested, you can either hand it over to a professional diamond evaluation lab or work something out with your local x-ray imaging center.
You begin by turning the stone upside down and placing it on a piece of newspaper. If you can read anything through the stone, or even see distorted black smudges, then it probably isn't a real diamond. A diamond would bend the light so sharply that you wouldn't be able to see the print.