 | A woman bought the 26.27-carat cushion-shaped white diamond ring at West Middlesex Hospital in Isleworth, west London, in the 1980s. She wore it every day for three decades, as she assumed it was not a genuine gemstone. The woman had assumed the ring wasn't worth much due to its shape, cut and lack of sparkle. “With an old style of cutting, an antique cushion shape, the light doesn't reflect back as much as it would from a modern stone cutting. Cutters worked more with the natural shape of the crystal, to conserve as much weight rather than make it as brilliant as possible.” The gem was expected to fetch about 350,000 pounds. ($454,000) There are a number of ways to easily test whether a loose stone is a real diamond or a fake. |
1) Scratch test. The “scratch test” involves simply scratching the loose stone against a mirror to test its hardness. When you think about this test in terms of the Mohs scale, however, this test proves inaccurate. Invented in 1812, the Mohs scale measures mineral hardness. Glass is rated a 5.5, and diamonds are a 10. So, genuine diamonds will scratch a mirror. On the other hand, so will quartz, moissanite, and cubic zirconia. Cubic zirconia are almost as hard to scratch as their diamond counterparts. Most well-made synthetic diamonds will seem authentic if you only use the scratch test.
2) Use a loupe. A loupe, which is a 10x jeweler’s magnifying glass, can tell you a lot about whether a diamond is real or fake. Fake diamonds, such as cubic zirconia or moissanite engagement rings, will look too perfect when examined under a loupe. All diamonds have their inclusions, and even Ideal cut diamonds will have some internal quirks. On the other hand, most fake diamonds are created to look totally flawless.
3) Fog Test. Creating a “fog” around the stone by blowing on it. A real diamond does not retain heat well. Even if you blow on it with hot air, it will not get foggy. On the other hand, a moissanite engagement ring will get a fog that then fades away, just like a mirror.
4) UV light test. This test is not as reliable as others. Many diamonds will glow blue under UV light. Jewelry stores always have high-powered UV lights to test and demonstrate diamond fluorescence.
5) The transparency test. A real diamond should refract light so intensely that you cannot see through it. Get a piece of newspaper or a page of a magazine and place the loose diamond on top of it. If the stone is a diamond with a decent cut grade, it should sparkle enough that you cannot see through it to read the words on the page.
6) Heat - Heat up the loose stone for about 30 seconds. Then, immediately drop the stone into a glass of cold water. A real loose diamond will not react at all, despite these extreme temperature changes. A fake diamond will likely crack or shatter.
7) Water - Because loose diamonds are so dense, they should sink to the bottom when dropped in a glass of water. Many diamond fakes – glass and quartz included – will float or not sink as quickly because they are less dense. This test is not foolproof; Heavy cubic zirconia and moissanite may have the ability to dupe it.
