A diamond should look brilliant and fiery in light, displaying a mix of white/gray sparkle (brilliance) and colorful flashes (fire or dispersion), reflecting white light outwards while projecting rainbow colors onto other surfaces, with the best cuts showing intense flashes and less "crushed ice" look in sunlight. Its unique light interaction means it reflects bright white and gray inside, but sends rainbow colors out, unlike fakes that often show rainbows inside.
When we take a diamond and look at it under any kind of light, we will see it shine and sparkle in white and sometimes gray-ish light. If we look at a stone under a lamp and notice a colorful rainbow, that means the stone is not a diamond.
Heat Test. The heat test is another easy and effective way to distinguish a real diamond from a fake. Heat the stone with a lighter for about 30 seconds, then drop it into cold water. Genuine diamonds withstand this thermal shock due to their robust molecular structure.
You may have heard that real diamonds only reflect white light. While it's true that they do reflect white light, authentic diamonds also reflect rainbow light.
Together, the beauty of a diamond comes from the “across-the-room-sparkle.” Few gemstones have this overall effect. We should remember that without light, diamonds have no brilliance, fire or scintillation. Light brings a diamond to life with an effect that few gemstones achieve.
Mobile apps may mimic testing, but they can't match the accuracy of professional instruments. Your phone won't replace a professional appraisal, but it can assist. Use the flashlight to observe how the stone handles light. A real diamond will produce sharp flashes and concentrated brilliance.
The Aquamarine name comes from the Latin word for seawater and is said to calm waves and keep sailors safe at sea. It is sometimes referred to as a poor man's diamond because of the pale color.
Buying a diamond starts by understanding the unique characteristics of each stone. After all, no two diamonds are the same. To help you make sense of shopping for these timeless gems, diamonds are graded based off the 4Cs - cut, color, clarity, and carat weight. The 4Cs of diamonds impact a stone's beauty and value.
Flashlight Test
To tell if a diamond is real with a flashlight, observe how the stone refracts light. Shine a flashlight directly at the diamond. A real diamond will reflect white light brilliantly, while a fake stone may not reflect as intensely or at all.
There are several types of fake diamonds in the market, but the most popular and convincing ones are cubic zirconia and moissanite. Both gemstones have unique characteristics that make them suitable substitutes for a real diamond, offering a similar shine and sparkle.
On average, a 1-carat diamond ring can range anywhere from $2,000 to over $10,000. For example, a flawless diamond with excellent color and cut will be priced at the higher end of the spectrum, while a diamond with slight inclusions or a warmer tone may be more affordable.
Real diamonds refract light in such a way that they offer exceptional sparkle, with sharp and quick reflections, while fakes often have a more muted sparkle or rainbow colors that are less defined.
A quick and easy test you can perform anywhere is the fog test. Diamonds: Diamonds are excellent at dispersing heat. If you breathe on a diamond, the fog from your breath should dissipate almost instantly, leaving the stone clear. Crystals: Crystals like cubic zirconia or glass do not disperse heat as efficiently.
It's important to remember that diamonds are the hardest stone on the Mohs Hardness Scale, making it nearly impossible to scratch them unless done so by another diamond. If you're willing to risk it, take a knife and gently scratch the surface of your stone. If it scratches immediately, the stone is synthetic.
No, a jeweler generally cannot tell if a diamond is lab-grown just by looking at it with the naked eye; they need specialized, lab-grade equipment like GIA iD100 or X-ray luminescence (XRL) testers to detect subtle differences in growth patterns, impurities, or fluorescence, as lab-grown diamonds share the same chemical and optical properties as natural diamonds. While some jewelers have machines to test, professional grading labs (like GIA) use advanced methods to identify them, often relying on laser inscriptions and grading reports for confirmation.
A 20-carat diamond is quite large, weighing 4 grams (0.141 ounces) and appearing roughly the size of a large pea or small bean, with a round cut measuring around 17.6mm across, though its actual visual size depends heavily on the cut, shape, and proportions, with fancy shapes sometimes appearing larger for the same weight.
Red diamonds are the most expensive colored diamonds per carat, often exceeding $1 million per carat due to their extreme rarity. Only 20-30 natural red diamonds are known to exist worldwide.
Real diamonds don't fog up as long. If you take the stone and breathe on it—whether it's real or fake—it will fog up, just like a mirror. The difference, however, is in how long the fog lasts on the stone's surface. With real diamonds, the fog will disappear quickly because diamonds conduct heat.
Pure diamond is not magnetic.
Can fake diamonds pass diamond tester? Yes, some diamond simulants can pass a diamond tester. For example, moissanite, a man made gem, may pass as a diamond on a standard tester pen.
A real diamond appears gray and white inside (brilliance) when held to the light and can reflect rainbow colors (fire) onto other surfaces. A fake diamond will display rainbow colors within the stone when held up to light.
The carat itself does not contribute to sparkle since brilliance is more dependent on cut and clarity. However, a carat larger may also mean there are more facets that catch the light, thus increasing the brilliance. Ultimately, what brings about the sparkle is the quality of the cut and clarity.