The world jewelry confederation set rules for grading laboratories such as the gemological institue of america or gia, american gem society or ags that have specific requirements for their grading system and criteria for grading clarity in diamonds.
The two most respected gemological laboratories in the world today are GIA, Gemological Institute of America, and AGS, American Gem Society. The grading guidelines that each of these two laboratories have set up meet and exceed CIBJOs, , Conf�d�ration International de la Bijouterie, Joaillerie, Orf�vrerie des Diamantes, Perles et Pierres, or more simply, The World Jewelry Confederation, rules, and have set the bar for all other laboratories. Each has their own nomenclature for their respective grading systems.
GIA uses the following labeling in their grading system:
13FL: Flawless
14IF: Internally Flawless
15VVS1 and VVS2: Very, Very Small Inclusions (two separate grades)
16VS1 and VS2: Very Small Inclusions (two separate grades)
17SI1 and SI2: Small Inclusions
18I1 and I2: Inclusions Visible
AGS uses a numerical system that runs from 0 to 10 in its grading system. Side by side, the two systems line up as so:
0 = FL
1 = IF and VVS 1
2 = VVS 2
3 = VS 1
4 = VS 2
5 = SI 1
6 = SI 2
7 = I1
8 = I1 and I2
9 = I2 and I3
10 = I3
You can see that the two systems have slightly different range of the particular grades. What is important to remember with this is that the nomenclature for a particular grade may be different, but the grading criteria and requirements for each are quite rigorous and strict, more so than the laboratory grading systems found elsewhere.
There are other fine gemological laboratories that follow the lead of GIA and AGS, which are quite capable of producing good results. However, as mentioned previously, these labs are not as stringent in their grading requirements as GIA or AGS, and so can, occasionally, produce a diamond certificate with a grade that would be higher than the grade that the same diamond would receive from GIA or AGS.
For example, EGL, European Gemological Laboratory, and the IGI, International Gemological Institute, both share the same scale nomenclature as GIA, however, they do not grade as stringently as GIA. A diamond graded by GIA (or AGS) of SI1 or higher will typically be considered "eye clean" (inclusions cannot be seen with the unaided eye). However, the same "eye clean" range would typically begin at VS2 as graded by both EGL and IGI, as they inflate their grades.
A good example of this is the SI3 grade. The SI3 was first put into use by EGL. The grade came about as a response to the growing jewelry industry concern that the gradation between the SI2 and the I1 grade was too great a leap. As a result, the SI3 grade was created to allow for a middle grade between the SI2 and the I1. The SI3 grade has been accepted by the Rapaport Diamond Report (also known as the Rap sheet: used as one of the industry's primary diamond pricing guides) as an acceptable and distinct grade of diamond for the sake of pricing. However, GIA does not recognize the SI3 grade and so does not use the SI3 on its grading system. When seeing the SI3 grade, be aware that this grade converts to an I1 on GIA scale.
As you have looked into diamonds and diamond grading you probably have discovered that there is more than one gemological laboratory that will assign a diamond-grading certificate. It is important to be aware of the fact that not all laboratories are as well respected or as stringent in their grading as every other laboratory.
Since 1975, any laboratory that wants to be recognized as a genuine gemological laboratory must follow the certification rules as laid out by CIBJO. CIBJO was formed in 1961 by multiple national jewelry trade organizations, in an effort to form an international jewelry confederation that could lie out uniform rules for the grading of diamonds. CIBJO currently has 21 countries involved in its associations. Their rules are the basic rules of grading today, such as: using a 10x loupe for grading; that each diamond to be certified must be graded by at least three (3) professional graders; that all laboratories must be independent and impartial and cannot be involved in the buying or selling of diamonds.
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The two most respected gemological laboratories in the world today are GIA, Gemological Institute of America, and AGS, American Gem Society. The grading guidelines that each of these two laboratories have set up meet and exceed CIBJOs, , Conf�d�ration International de la Bijouterie, Joaillerie, Orf�vrerie des Diamantes, Perles et Pierres, or more simply, The World Jewelry Confederation, rules, and have set the bar for all other laboratories. Each has their own nomenclature for their respective grading systems.
GIA uses the following labeling in their grading system:
13FL: Flawless
14IF: Internally Flawless
15VVS1 and VVS2: Very, Very Small Inclusions (two separate grades)
16VS1 and VS2: Very Small Inclusions (two separate grades)
17SI1 and SI2: Small Inclusions
18I1 and I2: Inclusions Visible
AGS uses a numerical system that runs from 0 to 10 in its grading system. Side by side, the two systems line up as so:
0 = FL
1 = IF and VVS 1
2 = VVS 2
3 = VS 1
4 = VS 2
5 = SI 1
6 = SI 2
7 = I1
8 = I1 and I2
9 = I2 and I3
10 = I3
You can see that the two systems have slightly different range of the particular grades. What is important to remember with this is that the nomenclature for a particular grade may be different, but the grading criteria and requirements for each are quite rigorous and strict, more so than the laboratory grading systems found elsewhere.
There are other fine gemological laboratories that follow the lead of GIA and AGS, which are quite capable of producing good results. However, as mentioned previously, these labs are not as stringent in their grading requirements as GIA or AGS, and so can, occasionally, produce a diamond certificate with a grade that would be higher than the grade that the same diamond would receive from GIA or AGS.
For example, EGL, European Gemological Laboratory, and the IGI, International Gemological Institute, both share the same scale nomenclature as GIA, however, they do not grade as stringently as GIA. A diamond graded by GIA (or AGS) of SI1 or higher will typically be considered "eye clean" (inclusions cannot be seen with the unaided eye). However, the same "eye clean" range would typically begin at VS2 as graded by both EGL and IGI, as they inflate their grades.
A good example of this is the SI3 grade. The SI3 was first put into use by EGL. The grade came about as a response to the growing jewelry industry concern that the gradation between the SI2 and the I1 grade was too great a leap. As a result, the SI3 grade was created to allow for a middle grade between the SI2 and the I1. The SI3 grade has been accepted by the Rapaport Diamond Report (also known as the Rap sheet: used as one of the industry's primary diamond pricing guides) as an acceptable and distinct grade of diamond for the sake of pricing. However, GIA does not recognize the SI3 grade and so does not use the SI3 on its grading system. When seeing the SI3 grade, be aware that this grade converts to an I1 on GIA scale.
As you have looked into diamonds and diamond grading you probably have discovered that there is more than one gemological laboratory that will assign a diamond-grading certificate. It is important to be aware of the fact that not all laboratories are as well respected or as stringent in their grading as every other laboratory.
Since 1975, any laboratory that wants to be recognized as a genuine gemological laboratory must follow the certification rules as laid out by CIBJO. CIBJO was formed in 1961 by multiple national jewelry trade organizations, in an effort to form an international jewelry confederation that could lie out uniform rules for the grading of diamonds. CIBJO currently has 21 countries involved in its associations. Their rules are the basic rules of grading today, such as: using a 10x loupe for grading; that each diamond to be certified must be graded by at least three (3) professional graders; that all laboratories must be independent and impartial and cannot be involved in the buying or selling of diamonds.
Call Us Toll-free 800-603-9940
Investor Relations |
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