Gemstones that mimic diamonds—like cubic zirconia or moissanite—are rising in popularity because of their beauty and affordability.
In this guide, we’ll cover the main differences between a real diamond and a fake diamond, then outline the best ways to test whether you have a genuine diamond or not.
Keep in mind that consulting a diamond expert is always the best way to confirm if you have a real diamond or not.
Gemstones like cubic zirconia and moissanite can be tough to differentiate from diamond if you don’t have the right tools!
Real diamond vs. fake diamond
A diamond is a naturally occurring crystal that forms below the ground under immense heat and pressure. Diamonds are traditionally desirable because of their beauty and rarity.
A real diamond has a unique crystal structure that a diamond expert can easily spot.
One way that diamond is unique is in its hardness. Diamond is the hardest naturally occurring material—a 10 on the Mohs Scale. Diamond is also very thermally conductive, meaning heat can very quickly pass through it.
Discovering and mining diamonds can be very expensive. Because of this, a lab-grown diamond is often much cheaper to produce.
A lab-grown diamond, also called a lab diamond or synthetic diamond, is (evidently) a diamond that is grown in a laboratory.
A lab diamond is physically and optically identical to a natural diamond. Its similar characteristics mean that even a diamond expert can’t tell the difference between a lab-grown diamond and a mined diamond.
A fake diamond (also known as a diamond simulant) is a different gemstone that looks similar to a diamond. Types of gemstones used as fake diamonds include cubic zirconia, moissanite, white sapphire, and white topaz.
A diamond simulant is often used because it is affordable yet still elegant. Two of the most common fake diamond gemstones are cubic zirconia and moissanite.
Cubic zirconia is a synthetic gemstone made from zirconium dioxide. Cubic zirconia is so popular because it looks very similar to diamond and won’t break the bank.
If you’re looking for elegant yet affordable jewelry, check out our collection of cubic zirconia rings.
When it comes to fake diamond, moissanite is the main competitor for cubic zirconia. Moissanite is a more recently produced imitation diamond made from silicon carbide.
Moissanite has a higher refractive index than diamond, which means it glitters more!
Using a diamond tester
A diamond tester is what an experienced jeweler will use to test whether you have a real or fake diamond.
A diamond tester measures the thermal conductivity of the diamond (how fast heat travels through it). This method is best because different gemstones have different levels of thermal conductivity.
But a thermal conductivity test can’t always tell the difference between diamond and moissanite because they are very similar.
To tell apart diamond and moissanite, you may have to use a moissanite tester. This device measures electrical conductivity instead of thermal conductivity.
Diamond inspection with a loupe
If you go to an experienced jeweler, they will likely use a loupe to inspect the diamond. A loupe is a tool that allows you to see the diamond under high magnification. A diamond expert can quickly tell a real diamond from a fake diamond this way by examining the crystal structure.
Not sure if you have a real diamond? Try these at-home tests
You can do many easy tests at home to work out whether your stone is a real diamond or a fake diamond. Keep in mind that these aren’t conclusive—the only way to be sure is to consult a diamond expert.
1. Check the mount and setting
If your diamond is in a piece of jewelry (rather than a loose diamond), check the surrounding mount and setting. If this is made with precious metal and appears high-quality, it is likely a real diamond.