Článek: manufacturing, certification... 19. 9. 2013

manufacturing, certification

Mined and graded natural diamonds make their way through the principal trading centres, such as De Beers’ ‘sights’ in London and Gaborone (Botswana), the Dubai Diamond Exchange (United Arab Emirates), the Shanghai Diamond Exchange, and the Israel Diamond Exchange, to one of the manufacturing centres in India, China, the USA, Belgium, Israel, and Armenia. There the diamonds are cut, polished and submitted for an expert’s opinion in an authorised certification laboratory. The diamond certificate (diamond grading report) above all explicitly proclaims that the crystal examined is a natural cut diamond. Without giving any price, it specifies the quality evaluated according to the standard four C´s classification criteria: carat weight, cut, colour, and clarity, along with other important parameters. Certificates for coloured (fancy) diamonds confirm the colour’s natural origin and, as the case may be, any modifications to the diamonds. In addition the diamond certificate gives the standard to which the report was carried out including the expert’s registration number, together with the date and personal signature of the appraiser responsible. The leading gemological laboratories have their professional establishments in the main world diamond trading centres (Dubai, Shanghai, New York, London, Antwerp, Ramat Gan, and Hong Kong). Customers usually have remote access (internet) to the database of the appropriate laboratory, where they can verify the authenticity of their certificate and thereby also the diamond. Among the leading gemological establishments are the Gemological Institute of America (GIA), HRD Antwerp, the International Gemological Institute (IGI), and others. The quality of the diamond, confirmed by the certifying laboratory, is the basis for determining the diamond’s value. The wholesale and retail price, as well as the overwhelming majority of traders, are guided by the weekly updated rates of the Rapaport Diamond Report, New York, sometimes also called the bourse price list. In effect, it is possible to trade diamonds all over the world, from the diamond bourses associated under the World Federation of Diamond Bourses (WFDB) to diamond clubs (the New York DDC, London, Johannesburg, and Sydney) and independent traders.