How to Tell a Real Diamond From a Fake: A Guide

If the diamond is already in a setting, such as a ring, you can typically determine the authenticity of the diamond by the quality of the metal. A real diamond will most likely be set in gold or platinum, so look for an engraving that says 10K, 14K, 18K, 585, 750, 900, 950, PT, or Plat. A C.Z. engraving is an instant giveaway that it’s fake, as it stands for cubic zirconia.