Diamond Certification & Certified Diamonds.

Diamond Certificates

Grading reports play an extremely important role in evaluating a diamond. They are important for the consumer as well as for the jeweler. A Diamond certificate gives security to the consumer that they are buying what the jeweler is promising them and for the jeweler they eliminate the mystery of grading an uncertified stone. A certified diamond secures and builds a relationship between the customer and the jeweler. It is thus important to understand a diamond certificate. A diamond grading report has complete information about the diamond. It describes the various factors determining the beauty, durability, value and quality of the diamond. It verifies and confirms the identity of the diamond. They are extremely helpful for insurance companies to replace your diamond as close as possible in the event of a loss or theft.

Accuracy of the certificate also depends on which laboratory is certifying or grading the diamond. In the USA, the GIA Gem Trade Laboratory is the top most authority in diamond grading. Their grading and measurements are the most accurate. In 2006 GIA changed it's diamond certificates and added one important aspect - Cut Grade, after almost a decade of research. This has enabled the end consumer in easily identifying a well cut diamond from a poorly cut diamond. The AGS (GIA's sister company) is also in the forefront. There are other laboratories like the European Gemological Laboratories, International Gemological Institute that are US Based and many other local gem labs. Popular European laboratories are Gubelin Labs of Switzerland and The Belgian Diamond High Council (H.R.D.) in Antwerp.

Anatomy of a Diamond Certificate.

Date: You have to make sure that the certificate is not very old. Usually a certificate, which is 2-3 years old, should stand good. In the case of an old certificate, usually 4 - 5 years old, you should make sure that there are no alterations done to the stone. This means that the stone should not be chipped or damaged in any other way. You can do this buy comparing the stone with the certificate.

Report Number: This is very important in case you loose your certificate. You can issue a duplicate certificate incase you loose your original.

Carat Weight: This mentions the exact weight of the diamond rounded to the hundredth of decimal e.g. 1.01 carats

Clarity and Color: This mentions the clarity and the color of the diamond. As you have already read in the 4 C's section this plays an important part in diamond prices.

Cut Grade: Since 2006, GIA has started grading the cut of diamonds and providing grades from Fair to Excellent. The gradings are based on several factors such as visual appeal, facet arrangement, pavilion facet angles, girdle percentages, etc. The cut grade is available only with round diamonds.

Shape/Cut: This mentions the cut of the stone i.e. old european cut, round brilliant cut, princess (square modified brilliant), etc.

Measurements/Dimensions: This part of the report has the measurements of the stone in millimeters to the hundredth of decimal. The measurements could be the highest diameter measurement and the lowest diameter measurements for a round. Fancy shapes have the length and the width. The diameter in round diamonds help you to decide whether the stone is round or out of round. The deviations between the diameters result in an out of round diamond. It is not possible to get a perfectly round diamond. Slight deviations are acceptable. The length and the width in fancy shapes decide whether the stone is too long or too short. Let's take an example of emerald cut. The length to width ratio in an emerald cut diamond should be between 1.50: 1 and 1.75: 1. Any deviations more than that makes it look too long or too short.

Proportions: They are usually mentioned in percentage or angles. The right percentage and angles result in an optimum balance of dispersion and brilliance. They consist of Table %: The table decides how much brilliance (white light) is reflected back to the eye. A majority of diamonds have their table percentage ranging from 53 % to 64 %.

Total depth %: This is very important. A diamond with a high total depth % (more than 63%) could add weight to the stone but no beauty. On the other hand low total depth percentage will look bigger to the naked eye than its weight. In both cases the stone looks dark when looking straight through the table.

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