Cultured or Synthetic?

You'll probably hear these stones referred to as both "cultured" and "synthetic" diamonds. Don't be confused by the propaganda wars -- both terms describe the same thing. The diamond growers, such as Apollo and Gemesis, understandably prefer "cultured" for consumers' familiarity with the term from the pearl market. But the GIA prefers to refer to the diamonds as "synthetics", reserving "cultured" for organic materials.

Types of Man-Made Diamonds

CZ (Cubic Zirconia)

The oldest of simulated diamonds, Zircons are available widely. In their best examples, CZ's are actually a fairly decent diamond replica. Unfortunately, the commodity-like availability and vast differences in quality have made the stone synonymous with low-cost fashion jewelry. CZ is considered by gemologists to be the best available diamond substitute. The similarities of Cubic Zirconia to a diamond are so remarkable that even gemologists can't always tell the difference when viewed with the naked eye.

Moissanite

Moissanite was discovered in 1893 in Arizona by Nobel Prize winner Dr. Ferdinand Henri Moissan in Diablo Canyon, site of a crater formed by a huge meteorite that struck the earth 40 thousand years ago. Dr. Moissan discovered bits of what looked like tiny diamonds. In 1905, these "tiny diamonds" were analyzed as silicon carbide, which was named moissanite in honor of Dr. Moissan. Moissanite is extremely hard, rating a 9.25 on the Mohr's hardness scale (diamond is 10.0). Its refractive index (brilliance) is slightly higher than diamond and it possesses twice as much fire (flashes of rainbow colors). Plus, unlike Cubic Zirconia, Moissanite doesn't cloud over time. Moissanite is much more expensive that Cubic Zirconia but still less than natural diamonds.

Diamond Nexus:

Gemstones are excellent diamond stimulants and come very close to matching the properties of mined diamonds at many different comparison points. They cut glass, being virtually identical to diamond on the Mohs (hardness) scale. They refract perfect "hearts and arrows" and have radiance and brilliance readings extremely close to flawless diamond.

Production of a Synthetic Diamonds

High Pressure, High Temperature (HPHT)

One of the methods used to create laboratory-grown synthetic diamonds is the High-Temperature High-Pressure (HTHP) technique (GE POL), using a four-anvil 'tetrahedral press,' or six-anvil 'cubic press.' A diamond seed is placed into a growth chamber and a combination of heat and pressure is applied to the 'seed' in a process that attempts to replicate the natural conditions for diamond-formation. The HTHP growth process can take 7 to 10 days to complete. Synthetic diamonds can also be treated with HTHP to alter the optical properties of the stones, making them difficult to differentiate from a natural diamond.

Chemical Vapor Deposition (CVD)

The 'Chemical Vapor Deposition' method was developed in the 1980s and uses a lower pressure growth-environment than HTHP. A seed or 'substrate' is placed in the growth chamber and a combination of heat and pressure is applied while vaporized carbon plasma, combined with hydrogen is applied (deposited) to the substrate in layers. The vaporized carbon gases are energized using microwave energy, and the entire growth process takes several days to complete.

Synthetic diamonds have grown in popularity in the past few years and will probably continue to do so. They are a viable option for someone who does not necessarily have the budget to buy a natural diamond. While the mining of diamonds works in ebbs and flows, the synthetic diamond market will continue to grow as technology advances.