You are at : Site Map > Education and Guidance > Understanding Diamonds > Diamond Certification Diamond Certification The Certification of Diamonds Every diamond is unique. And there is no such thing as the perfect diamond. While the classifications 'D' and 'IF', imply the very finest colour or internal flawlessness,  because diamonds are graded using a 10x lens or microscope, imperfections that would become visible under greater magnifications are in fact ignored. It’s in the interests of the customer and the jeweller to know the quality of the diamond they are buying and selling. Various gemmological laboratories around the world have established classification systems for the grading of diamonds. Each of these systems for grading diamonds is slightly different but the best known and commonly used systems are those of the GIA (Gemmological Institute of America) and HRD (Hoge Raad voor Diamant) in Antwerp. As these are both independent bodies they offer an unbiased assessment. A diamond certificate Also known as a diamond grading report, a diamond certificate is a verification of a diamond’s unique fingerprint. The certificate is created to independently identify the diamond and its characteristics, such as cut, colour, clarity and carat. The breakdown of a Diamond Certificate Unique reference number - the number that traces the diamond back to the laboratory where it was certificated. Date of certification - the date that the certificate is issued. Shape - the physical geometric shape of the diamond i.e. round, oval or square. Cutting Style - this is the way that the shape is achieved through the style of cut. There are three styles of cut: 'brilliant', 'step' and 'mixed'. Carat Weight - is stated in carats and is the unit of measurement of weight for diamonds (1 carat weights 0.2 grams). Dimensions - length, width and depth in millimetres of the diamond. A well cut 0.50cts diamond will have a diameter of 5.2mm. Clarity - measurement of the amount of inclusions within the diamond both internally and externally. Graded from 'FL - Flawless' down to 'I3 - Included'. Colour - the grade that assesses the absence of colour in a diamond. It runs from D - Z. Finish - includes polish and symmetry. Assessing the quality, accuracy and balance of the cut. Qualities of polish and symmetry are both graded from 'Poor' to 'Excellent'     view larger certificate Fluorescence - the measurement of the presence of natural blue fluorescence in a diamond under ultraviolet light. There are five different grades of fluorescence: 'None', 'Faint', 'Medium', 'Strong' and 'Very Strong'. Comments - additional observations and measurements not already mentioned within the diamond certificate. For example, 'Culet very small'. Clarity Map - a map that shows the size, type and position of the inclusions within the diamond when viewed under x10 microscope. Proportion Anatomy - a diagram which shows the depth (height from culet to table facet), table facet proportions (top of diamond), girdle thickness and culet appearance ('presence' or 'lack of'). Ralph Blacklock only sells diamonds that have been independently certificated by GIA or HRD. These are the two most respected Gemmological Laboratories. [ Diamond Colour ] [ Diamond Clarity ] [ Diamond Cut ] [ Diamond Carat Weight ] [ Diamond Certification ] [ Diamond Shape ] [ Diamond Care ] [ Diamond FAQ ]