Lab Created Diamonds
There is a significant difference between lab-created diamonds and diamond simulants. Cubic zirconia and moissanite are two examples of diamond simulants; both appear like diamonds but aren't. Diamond simulants command far higher prices than lab-created diamonds due to their superior chemical and physical qualities. It takes nothing more than a trained eye to tell a fake diamond from a lab-made one.
You can tell the difference between a lab-created diamond and a cubic zirconia using a diamond tester that measures heat conductivity. Some diamond testers may incorrectly identify lab-created diamonds and some natural colored diamonds as moissanites because of their similarities in electrical conductivity. Diamonds are single refractive whereas moissanites are double refractive, and this allows gemologists to tell them apart.