Up next in Buying, Spending, & Shopping Tips (19 videos)
Don't head to the mall or click "add to my shopping cart" without checking out the buying, spending, and shopping tips in these Howcast videos.
You Will Need
- Carat or gram scale
- Ultraviolet light
- Electronic diamond tester
Try the transparency test
Flip the diamond upside down and place it on a piece of newspaper. If you can read the newspaper through the diamond, it's not a real diamond.
Try the fog test
Hold the diamond in front of your mouth and breathe on it like you would if you were trying to fog a mirror. If the stone stays fogged for two to four seconds, it's a fake. A real diamond would disperse the heat before you could get it up to your eye
Try the weight test
Use a carat or gram scale to weigh the stone. The most common diamond fake is cubic zirconia, which weighs approximately 55 percent more than a diamond of the same shape and size.
Try the U.V. test
Hold the stone under an ultraviolet or black light. Many diamonds will display a blue fluorescence under a black light, while most fakes won't. However, a lack of blue fluorescence doesn't necessarily mean the stone is a fake. High-quality diamonds, which can be as much as 20 percent more valuable, don't show any fluorescence.
Examine the stone under a loop
Look at the stone through a loop, or jeweler's magnifying lens. A real diamond's facets will be sharp, not rolled. If the girdle is faceted or frosty, it's probably real, but if it's waxy and slick, it's probably fake.
Use a diamond tester
Ask a jeweler if you can use their tester, or if they will test the stone for you. Moissanite is the only stone than can fool an electronic diamond tester.
Look at the setting stamp
Look inside the setting for a stamp of "10K, 14K, 18K, 585, 750, 900, 950, PT, or Plat." If the setting is real gold or platinum, the odds are better that the stone is real. However, if there is a stamp of "C.Z.", the stone is a fake.