The color comparison table, after CIBJO, in force today therefore appears as follows:
CIBJO color Table 1986 |
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1) 2) |
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Hochfeines |
Blanc |
Exceptional |
Blanco extra |
D |
|
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WeiB + |
exceptional |
white + |
eccezionale + |
River |
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Hochfeines |
Blanc |
Exceptional |
Blanco extra |
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WeiB |
exceptional |
white |
eccezionale |
E |
|
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Feines WeiB + |
Blanc extra + |
Rare white + |
Blanco extra + |
F |
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|
Feines WeiB |
Blanc extra |
Rare white |
Blanco extra |
G Top Wesselton |
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|
WeiB |
Blanc |
White |
Blanco |
H |
Wesselton |
|
Leicht getbntes Blanc nuance |
Slightly tinted |
Blanco sfumato |
I |
Top Crystal/ |
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|
WeiB |
white |
J |
Crystal |
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Getbntes WeiB Legerement |
Tinted white |
Blanco logger- |
K |
Top Cape |
|
|
teinte |
mente colorito |
L |
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Getont 3) |
Teinte |
Tinted color |
Colorito |
M From Cape to |
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Z |
Yellow |
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Farbige |
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Diamanten |
Diamants de |
Fancy diamonds Diamanti colori |
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(Fantasiefarben) couleur speciale |
fantasia |
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1) As comparison |
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2) Transitional rule to 1990 |
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3) Optional classification possible (tinted 1.2.3.4) |
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Major changes in the new rules were as follows. The term "blue-white" was replaced by "exceptional white", and "lightly tinted white" by "slightly tinted white". The division of the first two colors, "exceptional white" and "rare white" into two sub-croups is permissible only for sizes of 0.47 ct and greater.
The terms, Top Crystal and Crystal, became "slightly tinted white" and From Cape to Yellow was included in "tinted". If desired, the range of "tinted" can be divided into 1-4.
The upper color zones of exceptional white (River 0) and rare white (Top Wesselton F) are indicated by the symbol +. The "old terms" were to be used only during the transitional period up to 1990 by way of supplement to these terms and have now only an indicative value.
The currently applicable color zones were determined by master stones selected primarily on a visual basis which are located at the lowest boundary of the color zone.
This official "original set" of CIBJO master stones consists of seven brilliants of approximately one carat each which have supreme validity for all of the nineteen countries affiliated with CIBJO. All members receive from the organization a duplicate set. and the rule is that each comparison set has to be confirmed by the CIBJO Commission.
The color is determined by an experienced grader by comparison with a master stone which has been standardized to a CIBJO master stone set using a light source of about 5000°/5500° Kelvin (055).
If there is no difference in color between the master stone and the diamond to be graded, the color designation of the master stone is to be applied. Should there be a difference in color, the darker color should be taken as correct reading.
color tones not in the yellow series (for instance those in the brown series) are similarly compared with the master stones.
Fancy colored diamond which have a clear and distinct color are to be designated separately a such.
Photometric measurements are not taken into account when determining the color of a diamond.
The fluorescence of a diamond is described but not evaluated using long wave UV (366 nm) and designated as
nil - weak - medium - strong.
| Comparison table of different color grading systems | IDC |