Synthetic diamonds are man-made stones. These stones were first produced in the early 1950's for mainly industrial purposes. Only recently have synthetic diamonds become available for commercial retail purposes. Synthetic diamonds are produced in a laboratory and they essentially have the same chemical composition and crystal structure of a natural diamond. Their physical and visual properties are almost the same as a natural stone as well. Synthetic diamonds are referred to as "Lab Grown", "Lab Created", "Created", Moissanite, “Signity Star Stone" and "Man-Made".
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.
Signity Star Stone
The Signity Star Stone is a type of man-made diamond, which never gets cloudy, even in shower, pool, or spa water. Signity Star is a high-grade cubic zirconia cut to ideal standards for maximum reflection. Signity Star stones are bright and sparkly and display more fire than the best grade of diamonds. Hardness rates at 8.5 on the Mohs Scale and they are known for their white color and internally flawless clarity.
Cubic Zirconia (CZ)
The oldest of simulated Zirconia’s, are widely available. Once considered a fairly decent diamond replica, the commodity-like availability and vast differences in quality have made the stone synonymous with low-cost fashion jewelry. CZ’s are fairly hard, 8-8.5 on the Mohs Scale, but only slight harder than most semi-precious gemstones. CZ’s do have a tendency to show fluorescence and will cloud over time.
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 Mohs Scale (diamond is 10.0). Its refractive index (brilliance) is slightly higher than diamond and it possesses twice as much fire diamonds. Plus, unlike Cubic Zirconia, Moissanite doesn't cloud over time. Moissanite is much more expensive than Cubic Zirconia but still less than natural diamonds. This is an excellent choice for a diamond substitute. Charles & Colvard Forever One™, the newest addition to the Charles & Colvard® family. A triumph of art, science, and sustained effort, Forever One™ is an unprecedented achievement with the extreme hardness and robustness inherent in all Charles & Colvard Created Moissanite®. Forever One™ is at the very pinnacle of the gemological scale, in the coveted D-E-F ranges and is a gem so pure, so white, so incredibly brilliant that it promises to change, forever, how fine jewelry is made and enjoyed. Forever One Moissanite is truly a diamond replacement as it surpasses a diamond in brilliance, fire, toughness, and luster.
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.