The appearance of the diamond certificate in 1970 fundamentally changed the way people think. Rules and laws have modified the market conditions: if deception or malice were frequent in diamond exchanges, procedures and official documents now exist which certify and authenticate the quality of a diamond.
Joaillerie Royale delivers a certificate in due form for your diamond on the basis of the criteria of the greatest laboratories, HRD, GIA, IGI.
Why is a certificate important?
To recognize a diamond in an indisputable way: in case of theft or simple repair, you are able to identify your diamond.
To make price comparisons between diamonds of equal quality, because, in the commercial circuit, this document is the guarantee of the value of a stone.
To make a precise evaluation of the diamond over time, which can be used by insurance companies in the event of a claim.
To negotiate: a diamond is more easily negotiable when it is certified, especially if it is set, because the setting does not allow reliable observation.
The nomenclature of diamonds is rigorously identical in all countries, the international standard being that given by the GIA (Gemological Institute of America). The latter, the HRD (Belgian national laboratory) and the International Gemological Institute (IGI) in Antwerp, the Chamber of Commerce and Industry of Paris (CCIP) are the reference organisations, reputed for their seriousness and integrity, because faced with the increase in the demand for certified diamonds, the expertise offices have multiplied.
The criteria mentioned in a diamond's certificate
A certificate is the diamond's identity card, i.e. its objective quality criteria, its own characteristics. This identification is the result of a sophisticated laboratory analysis.
The observation equipment used is highly sophisticated. Weighing is carried out on an electronic carat scale (accurate to one thousandth of a carat). The measurement is made to one hundredth of a millimetre:
For round stones, the diameter is measured on several axes. As a stone is never perfectly round, the certificate will always give 3 measurements: minimum diameter, maximum diameter and depth. Example: 5.36 - 5.40 x 3.30 mm.
For fancy shaped diamonds, the sides are measured.
Whatever the shape, the height of the culet at the table should be mentioned.
The diamond is observed with a binocular magnifying glass (40 times) to look for inclusions and determine its degree of purity. The defects (extra facets, quality of polishing, particularity of the inclusions, type of roundness, etc.), which are necessary to complete the identification of the stone, are notified during this examination and appear in the certificate area.
The colour of the diamond is analysed by comparison with standard stones. The spectrophotometer, coupled with a computer, also makes it possible to define the exact colour of the diamond.
The proportions and finish are analysed by placing the diamond in a profile projector. A mirror system allows the enlarged image of the diamond to be projected onto a glass support where reference marks are drawn. The deviation of the proportions makes it possible to determine the percentages of the table, crown and pavilion in relation to the diameter. This calculation is concluded by the assessment of the symmetry: Excellent, Very Good, Good, Fair.
