Sunday 25 June 2017

How To Read a GIA Diamond Grading Report


The diamonds for sale at Chain Me Up are graded for your information, but as they are below 1 carat they do not have a GIA report due to the cost involved in obtaining one.


GIA is the creator of the famous four C’s of diamond value and the international diamond grading system which sets the standards for diamond grading, making us the world’s most respected independent authority on diamond grading.


Each diamond submitted to the GIA grading laboratory is tested to be sure it is actually a natural diamond, a synthetic diamond and to see if it has been treated or not. Then it is graded independently by several highly trained graders.


This is an example of a GIA diamond report which details all pertinent information about a stones quality and characteristics. This is the date the report was issued. Each diamond is assigned a unique identification number. All the grading information for the diamond is stored in GIA’s global database under this report number. Some people choose to have GIA inscribe the report number on the diamond’s girdle to aid in identifying it. You can also inscribe a special logo, graphic or personal message. This line shows that this stone has been laser inscribed with the GIA report number.


This diamond has a round girdle outline and the facets are cut in the brilliant style. This is the stones minimum girdle diameter, the maximum girdle diameter and the diamond’s depth. For a fancy shaped diamond the measurements listed are length, width and depth.


The GIA report also has a facet diagram that approximates the shape and cutting style of the stone. Diamonds are weighed in carats. One carat equals one fifth of a gram. GIA records weight to the nearest one hundredth of a carat which is the internationally recognised practice.


GIA grades colourless and near colourless diamonds for the absence of colour when viewed through the pavilion from colourless to light yellow or brown by comparing them to GIA master colour comparison diamonds. The scale shows the relative position of the colour grades in the GIA colour scale. This stone, a ‘G’, falls in here in the near colourless range.


GIA graders examine diamonds for the presence of any internal and external characteristics. Based on the size, nature and number of any clarity characteristics found using a 10 power loupe, they assign a clarity range of flawless to included. Here is the GIA clarity scale, you can see that VS2 falls in the very slightly included range. Significant or identifying characteristics are marked on the facet diagram. The symbols represent the type, position and approximate size of a clarity characteristic and a key to the symbols used is below the diagram.


Here you can see how cut can affect the appearance of a diamond. This stone shows an even pattern of reflections, this one is dark in the centre and the facets are washed out. The GIA cut grade is used for round brilliant only and is based on the stones face up appearance, design and craftsmanship and it is listed here. This is the scale for the GIA cut grade ranging from excellent to poor. The angles and proportions of the diamond measured with an optical measuring device are presented on the report on this diagram.


Fish grades include polish which is the overall condition or smoothness of the diamond surface and symmetry which is the exactness of the diamond’s outline and the shape, placement and alignment of its facets.


If a diamond shows fluorescence to long-wave ultraviolet, the fluorescent colour and strength can help identify it. Blue is the normal colour of fluorescence in diamonds but it may be other colours. If there is no discernible fluorescence or it is very faint, GIA lists ‘none’ on the report.


Comments describe additional identifying characteristics that are not otherwise represented on the report as well as treatments and if the diamond is inscribed with a special logo, graphic or personal message it is listed here.


GIA diamond reports are highly valued, to ensure that you are in possession of a real report and not a fake or copy they include a suite of security components including a hologram, security screen and micro print lines in addition to several other propriety security features. The GIA diamond dossier is similar to a GIA diamond report but less expensive. It provides the same information as a GIA diamond report but it does not include a facet diagram and plot of clarity characteristics. Instead clarity characteristics are listed here. This is the only real difference between the information on a diamond dossier and a GIA diamond report and all diamonds submitted for a GIA diamond dossier are laser inscribed with the report number.


GIA is not affiliated with any retailer or wholesaler or manufacturer giving you peace of mind knowing that your GIA diamond report or diamond dossier represents the impartial opinion of unbiased professionals. It’s the difference between wondering and knowing.



How To Read a GIA Diamond Grading Report

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