While the appearance of diamond simulants is similar to that of natural diamonds, they are not diamonds. Common diamond simulants include glass and cubic zirconia (CZ), both of which are completely unrelated to diamond at the atomic level.
Simulants are, of course, less expensive than the real thing. They allow consumers to enjoy the flash and dazzle of diamond-like jewelry and to inexpensively compliment the latest fashion trend. But no matter how convincing the illusion, all diamond simulants have optical and physical characteristics that can be identified by a trained gemologist.
How does a GIA Diamond Grading Report help you know that your diamond is natural?
GIA tests every stone to verify that it is, in fact, diamond. GIA does not issue grading reports for simulants.