A diamond certificate is a report created by a team of gemmologists and can also be called a diamond grading report, diamond dossier or diamond quality document.
The diamond is assessed by collecting information about the stone using a trained eye, a microscope and other industry tools. A professional report is then created detailing the characteristics of the diamond, which include shape, carat weight, dimensions, colour, clarity, polish, symmetry and fluorescence. Cut grades are also provided for brilliant cut diamonds.
There are many independent laboratories. The four most consistent with their grading and most highly regarded in the jewellery industry are GIA, AGS, HRD and IGI.
GIA - The Gemmological Institute Of America
Established in 1931 as a non profit-making organization that provides gemstone identification, buying advice for consumers and training for members of the jewellery trade. It is one of the most respected laboratories in the industry. Every stone submitted is checked by a number of professional highly trained gemmologists to ensure an unbiased and consistent opinion.
AGS - The American Gem Society
Founded in 1934 by a small group of leading jewellers, its aim was to establish an independent organization to protect the consumer from fraud or false advertising. Its members are carefully picked, as it has a high code of ethics to follow. The Society opened its laboratories in 1996 and has developed its own standards for grading diamonds. As with its trade association the grading is consistent and consumer orientated.
HRD - Hoge Raad Vor Diamant
Based in Antwerp, the diamond high council is committed to serving jewellery professionals by offering products and services which benefit the diamond industry and trade. It was established in 1967 and has expanded into one of the largest diamond grading laboratories in the world. Certificates from HRD are highly regarded in the jewellery trade, as it has an excellent reputation for being objective and consistent with its grading.
IGI - International Gemmological Institute
This laboratory is one of the oldest in Antwerp. It was founded in 1975 and has since become the largest organizations of its kind, with laboratories and offices located all over the globe. This highly regarded organization is well known for its expertise and maintenance of a high level of service for industry professionals and consumers around the world.