Last updated on October 9, 2020
Have you ever wondered if the diamond you have received from your ancestors is real? You might be led to think that the gemstone is a genuine diamond just because your grandma told this. No doubt, she is a wise woman, but let’s find out how to tell if a diamond is real or fake with at-home tests (most of them are not conclusive), special equipment along with the help of experts.
At-Home Tests to Tell If a Diamond Is Real or Fake
The water test is one of the simplest ways to spot fake diamonds.
Get a drinking glass and fill it with clean water. Carefully drop the loose gemstone into the glass. If it sinks, it is a real diamond. If it floats underneath or at the surface of the water, you deal with a fake diamond.
Although this test might seem to be quite simple, it is based on gemstone’s density level. Real diamonds are incredibly dense (3.51 g/cm³) and usually outmatch the fakes in density test. However, keep in mind that good-cut cubic zirconia or glass is actually pretty heavy and could pass the water test as well.
The fog test is another easy method to tell a fake diamond from the real.
Real diamonds are heat resistant, meaning they never fog up the way glass or diamond alternatives do.
For the fog test, hold the stone between two fingers and breath on it. If the fog disappears right away, the diamond is real. If it takes a couple of seconds for the fog to dissipate, your stone is likely a fake diamond.
Before continuing with this test, you should be aware that if your stone is fake, this method will damage it.
Real diamonds are incredibly strong materials and extreme temperature changes do not affect their structural integrity.
To test this, take a drinking glass and fill it with cold clean water. Use fireproof gloves to hold the stone and heat it for 30 seconds with a lighter. Carefully drop the stone into the cold water. A real diamond wouldn’t be affected by the temperature change and simply sink to the bottom of the glass while a fake one would shatter.
Extreme heat and sudden switch to the cold water will ruin any stone other than a diamond, so don’t do this unless you are willing to ruin a fake stone.
Newspaper or Read-Through Test
The newspaper or read-through test is exactly what it sounds like – you need to read a text through the diamond. Be aware that this test suits only for loose stones.
Take the stone and place it flat side down onto a page of a newspaper or any other paper with lots of lettering. If you can read the letters, even if the letters are blurry, the diamond is fake.
It is impossible to read through a real diamond because its facets will refract the light in different directions. However, if the diamond has an atypical cut, this test won’t be reliable.
The sparkle test is a visual inspection of your stone in the light.
Take the diamond in question and hold it under a normal lamp and try to analyze what you see.
A real diamond reflects light very well, providing bright shimmers of white light and colourful light reflections. A fake diamond such as Cubic Zirconia sparkles with more iridescent colours, while an authentic diamond reflects light in a more “elegant” way. So if your stone sparkles in many colours, it is probably fake.
Expert Techniques to Tell If a Diamond Is Real or Fake
While at-home tests are fun and cost nothing, it is recommended to bring the stone in question to a diamond expert to get the answers.
Inspecting a Diamond With a Loupe or a Microscope
Diamond professionals use a special magnifying glass or a microscope to inspect diamonds and other gemstones. Under magnification, an expert will look for blemishes and imperfections within the stone.
While a fake diamond can be perfectly flawless, a real gem will have small imperfections even though they are not visible to the naked eye. So if the stone is too perfect, most likely it is not a real diamond.
Using a Diamond Tester
A diamond tester is a special tool used to indicate whether a stone is a real diamond based on its physical properties.
The principle of its operation is based on the fact that different gemstones have different chemical structure and thus they conduct heat and electricity differently. Meaning, heat or electricity will pass through a diamond in a different way than it would through Cubic Zirconia, for example.
It’s important to mention that the tester that measures only thermal conductivity cannot tell a real diamond from moissanites as these two stones are very similar when it comes to interaction with heat. The diamond testers that measure electrical conductivity are more accurate in such a case.