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  • Tanzanite International Grading System

    Colour - Tanzanite has what many would consider the finest blue hue in the world of gemstones, a color which often leaves even the finest sapphires lacking. The gem is strongly trichroic, and therefore appears to have several colours in the same stone: blue, violet and red. Good quality Tanzanite has an deep royal blue or violet colour. Colours range from rich royal blues or vibrant violet to paler watery shades, depending on whether the stone is blue or violet-dominant in colour. The colour dominance depends on whether the gem is cut and polished from the long or the short axis of the crystal shaped rough tanzanite; and the more intense the colour the better the quality.

    Blue Dominant:

    Light B-A-
    Medium
    B-A
    Good
    B-AA
    Very good
    B-AAA
    Exceptional
    B-AAA+
    Rare
  • Violet Dominant:

    Light

    V-A-
    Medium
    V-A
    Good
    V-AA
    Very good
    V-AAA
    Exceptional
    V-AAA+
    Rare

    Clarity:

    The clarity of a Tanzanite is graded in a similar manner to that of diamonds, and range between Internally Flawless (IF), and Included (I1-3). At Tanzanite International, we don't stock tanzanite with a lower clarity than VVS (Very very small inclusions). High clarity gives the stone added fire and brilliance, and significant inclusions could result the stone to crack or break, if pressure is applied.

    Grading Clarity:

    IF - INTERNALLY FLAWLESS
    VVS - VERY VERY SMALL INCLUSION (not visible under 6x)
    VS - VERY SMALL INCLUSION (slightly visible under 6x)
    SI - SLIGHT INCLUSION (clearly visible under 6x)
    I - INCLUDED (clearly visible to the eye)

    Cut:

    It is very important for a Tanzanite to be well cut, as it impacts not only on the brilliance and fire of your stone, but also on the overall quality. A badly cut tanzanite, can make the best quality look inferior, and often stones are cut to maximise weight and not beauty. At Shimansky, we stock only the best cut tanzanites, and all our tanzanites are graded for their cut as part of the certification process. As a rule, we only select fine cut stones.

 

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