A diamond certificate is a written professional gemological report from an accredited laboratory that explains and describes all of a diamond's attributes. This includes the information on the diamond such as its shape, measurements, diameter, length, width, weight, depth percentage, table percentage relative to the diameter, girdle characteristics, culet description, polish and symmetry conclusions, clarity, color, and fluorescence. A certificate also contains a front and back diagram of the diamond with a plot of its inclusions.
The certificate is like a record of the diamond's pedigree and it is your assurance that you are in fact receiving the diamond you have so carefully chosen. The certificate will also include the date, name and address of the laboratory and a certificate number that is registered in the database of that lab.
Certificates are also available other gemstones. They normally have the carat weight, shape, and dimensions of gemstone, color and clarity, type of gem, whether it has been treated in any fashion (most gemstones are treated), and sometimes if determinable the country of origin. The Swiss Gemological Laboratory or the American Gem Society usually provides these certificates.
A certificate is prepared by a certified professional using the most advanced of gemological instruments. There are a number of qualified, recognized laboratories around the world that issue diamond certificates, They include the Gemological Institute of America, the Diamond High Council in Belgium (HRD), the International Gemological Institute, the European Gemological Laboratory and the American Gem Society. Each is a respected and qualified laboratory and therefore, the report on your certificate will be honest and will not inflate or deflate the quality of your diamond.
Fancy color diamonds can have gemological reports that will describe the clarity and some that will only address the color. In fancy colored diamonds, the diamond grading report states the concentration of colors as follows: Fancy Light, Fancy, Fancy Intense, Fancy Vivid and Fancy Deep. Each of these terms will be followed by color or a combination of colors that the diamond possesses, including whether the color is evenly dispersed through the diamond or concentrated in certain parts, such as the center or the edges