2.3 Clarity Grading Scale
The subdivision and denominations of the clarity grades are as follows:
LOUPE-CLEAN
VVS1
VVS2
VS1
VS2
SI1
SI2
P1 ( I1 )
P2 ( I2 )
P3 ( I3 )
2.3.1. DEFINITION OF "LOUPE-CLEAN"
No diamond can be referred to as being 100% free of inclusions/internal characteristics. In all diamonds inclusions will occur. They belong to the essential character of the diamond. Therefore, the first clarity grade does not refer to diamonds being 100% inclusion free, but to diamonds being "loupe-clean", i.e. free of internal characteristics in so far as the diamonds are examined under a magnification of a loupe 10X. In particular, the definition generally accepted in the diamond industry states that:
A diamond is called "loupe-clean" if, after an examination by an experienced grader with a loupe 10X (corrected for spherical and chromatic aberration), it has been found free of internal characteristics.
It is recommended that the characteristics of the artificial light source used, approximate the C.I.E.-standard illuminant D65 (C.I.E. = Commission Internationale de I'Eclairage / International Commission on Illumination).
The recommended method is to make a direct comparison, using a loupe 10X, with a reference diamond, accepted by the IDC, containing an inclusion marking the limit of the loupe-clean-grade. In any case, whatever means of examination are used; the final decision must be made with a loupe 10X.
2.3.2. GRADING OF INTERNAL CHARACTERISTICS
The internal characteristics are graded as described in the following definitions, which are to be (valid for) used by an experienced grader.
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loupe-clean
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ref. 2.3.1.
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VVS :
VVS1
VVS2
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Very very small internal characteristic(s), which can be found from very hardly to hardly with a loupe 10x. The size, position, number and brightness of the internal characteristics determine the distinction between vvs1 and vvs2.
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VS :
VS1
VS2
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Very small internal characteristic(s), which can be found from fairly hardly to easily with a loupe 10x. The size, position, number and brightness of the internal characteristics determine the distinction between vs1 and vs2.
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SI :
SI1
SI2
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Small internal characteristic(s), very easy to find with a loupe 10x. The size, position, number and brightness of the internal characteristics determine the distinction between si1 and si2.
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P1 or I1
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Pique 1 or Included 1 Internal characteristic(s), which can hardly be found with the naked eye through the crown side of the diamond.
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P2or I2
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Pique 2 or Included 2 Large and/or frequent internal characteristic(s), easily visible to the naked eye through the crown side and which reduce(s) the brilliancy of the diamond slightly.
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P3 or I3
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Pique 3 or Included 3 Very large and/or frequent internal characteristic(s), very easy to be seen with the naked eye through the crown side and which reduce(s) the brilliancy of the diamond.
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2.3.3. GRADING OF EXTERNAL CHARACTERISTICS
External characteristics are graded as described in the following definitions, which are valid for use by an experienced grader.
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type of external characteristics
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grading of the external characteristics
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polishing faults or damages
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for diamonds without internal characteristics: the clarity grade becomes loupe-clean and the external characteristics are mentioned as :
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for diamonds with internal characteristics:
the external characteristics may influence the clarity grading
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not to find or very hard to find with a loupe 10X
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not to be mentioned
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no influence
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fairly hard to find with a loupe 10X
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mentioned as: negligible external characteristics
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no influence
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easy to find with a loupe 10X
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mentioned as: external characteristics
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may influence the claritygrading
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very easy to find with a loupe 10X
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separate description under "Comments " (example: important burning marks on crown side)
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may influence the clarity grading
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Major external characteristics, visible from the crown side, may influence the clarity grading.
When a diamond does not have any internal, but only external characteristics, it is referred to as being "loupe-clean” and a mention is made about the external characteristics. In case of diamonds with internal characteristics, the external characteristics can diminish the clarity grade.
2.3.4. GRADING OF STRUCTURE PHENOMENA
2.3.4.1. STRUCTURE PHENOMENA
The growth lines, the graining effects and the different forms of "knots", such as the twinning seams, knot lines and knot planes, are considered as "structure phenomena". The meaning of these terms is explained in the addendum "Types of structure phenomena in diamonds".
2.3.4.2. DESCRIPTION
The different kinds of structure phenomena can be divided into the following groups:
A. Structure phenomena that are only externally visible (e.g. surface grain lines, twinning lines, knot lines).
B. Structure phenomena that are internally visible, but are not causing any colour effects or white reflections (e.g. growth lines and (some) various? kinds of graining)
C. Structure phenomena that are internally visible and are causing colour effect or white reflections (e.g. brownish coloured zones, reflective grain planes and (some) various? kinds of graining).
The rules for grading the structure phenomena of groups A and B are as follows:
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visibility of the structure phenomena
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diamonds without internal characteristics
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diamonds with internal characteristics
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not to be found or very hard to find with a loupe 10X
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- clarity grade : "loupe-clean"
- no remarks
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no influence on the grading of the internal characteristics
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hard to find with a loupe 10X
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- clarity grade : "loupe-clean"
- description under "Identification Marks" - minor surface grain lines
- minor graining
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no influence on the grading of the internal characteristics
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fairly easy to find with a loupe 10X
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- clarity grade : "loupe-clean"
- description under "Comments"
- surface grain lines
- graining
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no influence on the grading of the internal characteristics
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easy to find with a loupe 10X
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the structure phenomena influence the clarity grading
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the structure phenomena may influence the clarity grading
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visibility of the structure phenomena
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diamonds without internal characteristics
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diamonds with internal characteristics
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not to find with a loupe 10X
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- clarity grade : "loupe-clean"
- no remarks
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no influence on the grading of the internal characteristics
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very hard to find with a loupe 10X
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- clarity grade : "loupe-clean"
- description under "Identification Marks"
- minor graining
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no influence on the grading of the internal characteristics
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hard to find with a loupe 10X
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- clarity grade : "loupe-clean"
- description under "Comments"
- graining
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no influence on the grading of the internal characteristics
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fairly easy to find with a loupe 10X
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the structure phenomena influence the clarity grading
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the structure phenomena may influence the clarity grading
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