Wednesday, May 30, 2012

Synthetic versus natural diamonds: HRD Antwerp helps you to tell the difference

HRD Antwerp has developed a compact screening device, “D-screen”, which distinguishes natural from potentially synthetic colourless or near-colourless polished diamonds. For the large majority of near colourless polished diamonds on the market, D-Screen guarantees that the diamond is not-synthetic and not-HPHT treated. For the number of stones that are referred for further examination, an additional investigation in a reliable laboratory is necessary.
Example of a damaged coating on the surface of a polished diamondFor the most part, rough synthetic diamonds can be visually distinguished from their natural counterparts by their external shape. However, this visual identification is no longer possible after the diamond is polished. Even the study of inclusions using a microscope does not provide a conclusive answer.
The production of synthetic diamonds started in the 1950s, and they now comprise over 95% of the industrial diamond market. Synthetic diamonds of gem quality were already present in small quantities on the gem diamond market in the 1970s. It has only been recently that synthetic diamonds have begun to really impact the gem diamond market.
HRD Antwerp has invested significantly in know-how and technology to identify these synthetic stones.
But while a well-equipped grading lab has all the necessary instruments to conclusively identify synthetic diamonds, their sophisticated equipment is not readily available to the individual diamond trader. Therefore, HRD Antwerp developed a compact screening device for traders to use in their office or elsewhere. By screening the diamonds, “D-Screen” can distinguish between natural diamonds and potentially synthetic or treated ones. The instrument tells whether a diamond passes the test or is recommended for further examination in the diamond lab. 
NOTE: The  “D-screen” is  NOT designed for Laboratory work.

1 comment:

  1. Synthetic diamonds are sometimes referred to as laboratory-created diamonds, laboratory-grown diamonds, or cultured diamonds, and are manufactured diamond crystals produced by man, not nature.

    Synthetic diamond can be optically and chemically identical to natural diamond.
    Gem-quality synthetic diamonds are predominantly cubic and octahedral in the rough form. Impurities are common, but as the technology has progressed so the rough diamond crystals have improved. A diamond's hardness can vary depending on its impurities and crystalline structure.

    Although synthetic diamonds have similar structure and chemical properties to a natural diamond, they can be conclusively identified by differences in atomic structure and trace impurities due to their different growth environment.

    Colour zoning, inclusions, fluorescence and other properties of synthetic diamonds provide practical visual indicators using standard gemmological techniques and equipment, but conclusive identification requires advanced equipment and trained technicians in a laboratory.

    Synthetic diamonds can sell at a fraction of the cost of natural diamonds, because they are made for less than it costs to mine a natural diamond. For this reason they are a viable alternative to natural diamond or less durable simulants.

    DCLA does not certify synthetic diamonds, but laboratories that do opt to certify synthetic diamonds must clearly state on the certificate that the diamond is a laboratory-created, synthetic diamond.

    There are currently two known processes for growing synthetic gem-quality diamonds: the High Pressure High Temperature (HPHT) method, and the Chemical Vapour Deposition (CVD) method.



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