LAB GROWN DIAMONDS
The formation process of Natural Diamonds occurs at depths ranging from approximately 150 km to 700 km, under geologically and mineralogically favorable conditions for the genesis, development, and ascent of crystals. These processes take an extremely long time (we're talking about processes that require billions of years) from formation to extraction in mines. On the other hand, the methods used for the production of Lab-Grown Diamonds involve a period of just a few weeks.
The production processes currently available for the laboratory creation of Lab-Grown Diamonds are the HpHt (High Pressure-High Temperature) method and the CVD (Chemical Vapor Deposition) method.
The HpHt process involves the insertion of pure Carbon powder inside a press, with temperatures of around 1300°C - 1600°C and pressures of about 5-6 GPascal. To understand the effect of pressure, imagine the entire weight of a passenger airplane resting on one's fingertip. As for the production costs, it's important to consider that these pressures and temperatures are maintained for a period of approximately 2-4 weeks, during which carbon atoms begin to grow around the seed crystal until the desired carat weight is achieved.
WHAT IS THE MANUFACTURING PROCESS?
The CVD process involves the deposition of carbon inside a vacuum chamber through the combustion, at very high temperatures, of a mixture of hydrogen and methane. Carbon, layer by layer, is deposited above a seed crystal, thus creating a uniform surface. The time required for the formation of rough material suitable for the production of a 1.00 carat cut gem is approximately four weeks.
Despite Lab-Grown Diamonds being a product grown in a laboratory and differing in genesis from Natural Diamonds, their chemical and physical characteristics do not substantially differ from the latter. Therefore, hardness, density, refractive index, dispersion, and chemical composition are identical to Natural Diamonds extracted from mines.
Lab-Grown Diamonds are not classified as or considered among existing imitations, such as Corundum, Moissanite, Cubic Zirconia, Fabulite, etc. Instead, they are effectively the direct counterpart of Natural Diamonds, artificially created by humans.
Here is a comparative table of the main physical-optical characteristics of Natural Diamonds, Lab-Grown Diamonds, and their imitations.
Although the chemical and physical characteristics of Lab-Grown Diamonds are identical to those of natural diamonds, there are a series of highly sophisticated gemological investigations such as FTIR, UV-VIS-NIR, UV fluorescence, and phosphorescence at different wavelengths that help us identify their synthetic origin.
To date, we cannot rely on an exclusive method that allows us to conclusively determine the origin of the material we are analyzing. Instead, we need to collect more data and use various methods to provide a comprehensive and reliable diagnosis.