CIBJO has laid down the following ratified regulations in 1986 for the Clarity grades:
All internal faults and features which are completely or partially surrounded by the stone, are to be counted as inclusions. These can be:
- crystalline or solid inclusions, clouds, dot-like inclusions
- cracks, feather- or fan-like inclusions, fringes on the girdle
- structural defects (only in as far as they are clearly visible in the stone as listed under (2), for instance brown growth lines or twinning lamellae, reflecting growth planes).
The clarity of a diamond is to be tested by a practiced expert with a 10 x magnifying achromatic, aplanatic loupe under normal light and graded as follows:
- Loupe clean
A diamond can only be designated as loupe clean, if it is shown to be completely transparent and free from inclusions under the above conditions.
- VVS (VVS 1 VVS2)
Very, very small inclusions, very difficult to recognize under 10 x magnification.
- VS (VS 1 VS 2)
Very small inclusions, difficult to recognize under 10x magnification.
- SI SI1, SI2
Small inclusions, easily discernable under 10 x magnification, not visible through the crown with the naked eye.
- P1 (Pique 1)
Inclusions can be seen easily under 10 x magnification, but do not influence brilliance. Just visible with the naked eye through the crown.
- P2 (Pique 2)
Larger and/or numerous inclusions, which can be seen through the crown with the naked eye and which influence the brilliance somewhat.
- P3 (Pique 3)
Large and/or numerous inclusions, easily visible with the naked eye and damaging to the brilliance.
Terms such as "pure", "eye-clean" and "commercially clean" and other misleading
descriptions are not to be used.
The sub-division of the clarity grade VVS, VS and SI into two sub-groups each is only allowable for size of 0.47 ct. and above.
- External features do not affect clarity. These include in particular:
-cut traces, rough edges and corners, burnt facets and very thin-whiskered girdles;
_ surface damage such as scratches and dot-shaped blow indentations;
_ additional facets and rough crystal and residual areas (naturals);
_ twinning lines (graining), growth lines.
Larger external features which can be removed only with a considerable loss of weight should be taken into consideration in determining clarity
- Transitional rules for Scandinavia: The Scandinavian countries were using clarity grading during a transitional period up to 1990.
|Origin of clarity grades and determination of nomenclature||Scan.D.N.|