What is a “Synthetic” Diamond?

Technically, a synthetic diamond is one that is created by artificial, rather than geological, means. The term “synthetic” encompasses many other terms related to diamonds including “man-made,” “lab-created,” “laboratory-grown,” “cultured diamond,” and “cultivated diamond.” These diamonds, like natural diamonds, are made from carbon and have the same refractive index, density, hardness, dispersion, and crystalline structure as those diamonds mined from the Earth. Synthetic diamonds are often confused with another non-natural diamond called a “diamond simulant,”. One of the most common methods of creating synthetic diamonds is Chemical Vapor Deposition (CVD).

Chemical Vapor Deposition

First produced about ten years ago, CVD diamonds are relatively new to the jewelry market. As the name suggests, carbon-based gases are heated to extremely high temperatures inside the CVD machine until the molecules break apart, releasing the carbon atoms. These atoms rain down onto a diamond substrate at the bottom of the machine, building up on one another like snowflakes to form the layers of the diamond. Many of the early CVD diamonds were black or brown, but scientists found that by changing the gases in the machine and treating the gases at high temperatures and high pressure, colorless diamonds could be created. Today, it can be very difficult to tell the difference between a natural diamond and a CVD diamond.

Diamond Simulants

These stones may look like a diamond to the naked eye, but technically, they are very different. Far less expensive than both natural and synthetic diamonds, diamond simulants include such materials as Cubic Zirconia (CZ), high-leaded glass,white sapphire, moissanite, and Yttrium aluminum garnet.None of the simulants are created solely from carbon, and only CZ and YAG have the same crystalline structure as a natural or synthetic diamond. The density, refractive index, and dispersion are all different compared to those of a diamond, and all the simulants earned a softer rating than the diamond’s “10” rating on the Mohs Scale.

Cubiz Zirconia

One of the most popular diamond simulants is Cubic Zirconia. Available on the jewelry market since 1976, CZ is created from zirconium dioxide, making it heavier than a natural diamond. The added weight makes it more difficult for light to pass through the stone easily, giving the CZ a lower refractive index (and therefore less brilliance) than the natural diamond. While the affordable price of the CZ is enticing, many diamond aficionados agree that they look “too perfect,” making them unrealistic substitutes for diamonds.

Moissanite

First discovered in 1893 by Henri Moissan, this diamond substitute is relatively new to the jewelry industry. Moissan initially thought the silicon carbide crystals he found in a meteor crater in Canyon Diablo, Arizona were diamonds; however, upon closer inspection he found this mineral to have a different chemical composition than a diamond. The mineral was named “Moissanite” later in Moissan’s life, after its discoverer.

Occurring naturally in meteorites, and as inclusions in diamonds, xenoliths, and ultramafic rocks, Moissanite is very rare in its natural form. Due to the scarcity of this mineral, today’s Moissanite is manufactured in laboratories for use in jewelry, making it one of the most available synthetic diamonds.