How to Spot Fake Diamond Engagement Rings: Tips and Tests for Authenticity

While it may seem difficult to tell a real diamond from a fake, a few visual cues can help you make an educated guess before turning to more technical tests.

In short: Spot a fake diamond using four quick tests: a real diamond reads positive on a moissanite/diamond tester, has Mohs 10 hardness, is transparent under shortwave UV in most cases, and shows sharp facet edges with no doubling. A current GIA or IGI report with girdle inscription is the definitive proof. Cubic zirconia and moissanite are the most common imitants.

Brilliance and Fire

Real diamonds are known for their brilliance (how they reflect white light) and fire (how they disperse colored light).

Fake diamonds often sparkle less intensely, giving off a duller shine.

If you notice that your diamond isn't dazzling in the light as much as you'd expect, it could be a fake.

Inclusions and Flaws

No diamond is perfect.

Real diamonds typically have small inclusions or flaws that occur during their natural formation.

If the diamond you're inspecting looks too perfect—flawless and without imperfections—it may be a fake.

Genuine diamonds usually have slight marks, which can be visible under a jeweler’s magnifying glass.

Weight and Size Comparison

A real diamond is less dense than most diamond simulants, meaning a fake diamond may feel heavier than an authentic one of the same size.