LAB GROWN DIAMONDS
The formation process of Natural Diamonds requires depths between approximately 150 km and 700 km and geological-mineralogical conditions favorable to the genesis, development and rise of the crystals. All this happens over extremely long times (we are talking about processes that require billions of years) from formation to extraction in the mine. The methods applied for the production of Lab-Grown Diamonds instead take a period of a few weeks.
The production processes currently available for the creation of Lab-Grown Diamonds in the laboratory are the HpHt method and the CVD method, respectively High pressure-High temperature and Chemical Vapor Deposition.
The HpHt process involves the insertion, inside a press, of pure carbon powder, with a temperature of approximately 1300°C – 1600°C and a pressure of approximately 5-6 GPascal. To understand the effect of pressure you need to imagine that an airliner places all its weight on a person's finger. And to have an idea of ​​production costs it is necessary to consider that these pressures and temperatures are maintained for a period of approximately 2-4 weeks and that the carbon atoms begin to increase around the crystalline seed until they reach the desired carat weight.
WHAT IS THE MANIFACTURING PROCESS?
The CVD process, on the other hand, involves the deposition of Carbon inside a vacuum chamber through the combustion, at very high temperatures, of a mixture of Hydrogen and Methane. The Carbon, layer after layer, is deposited on top of a seed crystal, thus creating a uniform surface. The time required for the formation of raw material suitable for the production of a 1.00 carat cut gem is approximately 4 weeks.
Although Lab-Grown Diamond is a product grown in the laboratory and differs in genesis from Natural Diamond, the chemical-physical characteristics do not differ substantially from the latter. Therefore the Hardness, Density, Refractive Index, Dispersion and Chemical Composition are identical to Natural Diamond mined.
The Lab-Grown Diamond is not and is not among the existing imitations, such as: Corundum, Moissanite, Cubic Zirconia, Fabulite etc... but it is in all respects the direct correspondent of the Natural Diamond, created artificially by man.
Comparative table of the main physical-optical characteristics of Natural, Lab-Grown Diamonds and their imitations.
Although the chemical-physical characteristics of Lab-Grown Diamonds are identical to the properties of natural Diamonds, there are a series of extremely sophisticated gemological investigations such as FTIR, UV-VIS-NIR, UV fluorescence and phosphorescence at different wavelengths that help us to identify its synthetic origin.To date, we cannot rely on an exclusive method that allows us to trace with certainty the origin of the material we are analyzing but we need to collect more data and use different methods to provide a complete and reliable diagnosis.