Like diamond, tanzanite quality is also set on the 4C basis where color is the first C followed by clarity, cut and carat.
The color of tanzanite is the most important factor in determining the quality of the stone. Tanzanite shows trichroism in which the same piece of gem exhibits three different colors in different light conditions. It also depends on the orientation of the stone.
The color of tanzanite is decided on the basis of 5 grade color system. The highest color grade is AAA which stands for deep and vivid blue tanzanite with high trichroism. Tanzanite of this color grade is rarest and very expensive. The tanzanite jewelry with AAA grade exhibits a beautiful play of colors in different lights.
The next color grade is A with slightly de-saturated color tones. Although the hues are comparatively less intense then AAA grade, the grade A tanzanite are also highly demanded as they also show the trichroism. This color grade is highly sought after for jewelry.
While going down in the color grading, faded and highly faded tanzanite are considered in B and C grade. These are not good for jewelry as they don’t have the required luster and hues and also seldom change the color.
While buying tanzanite jewelry the clarity also plays a major role. As tanzanite is a type 1 gemstone so the better the clarity the better the quality! The clarity grading system of tanzanite is similar to diamond. It starts from VVS at 10X magnification followed by VS, SI and I1-3. Very-very slight inclusions (VVS) grade tanzanite are most expensive and rare. So buyers usually consider VS or SI grades in tanzanite jewelry.
Carat is the standard measurement of gemstone weight. The basic principle in case of tanzanite is – the more the weight, the rarer the stone. But a smaller stone with better color and clarity will cost more because color and clarity are the main defining features of tanzanite.
Cut is the final C of tanzanite quality measurement which focuses on an orientation based proportionate shape. A tanzanite cut in a shape which is maximizing the brightness along with better trichroism presentation demands more cost.
You can find tanzanite in almost every shape from regular cuts like round, oval, pear, trillion, cushion, marquise to fancy cuts like princes, checker etc.
By understanding the 4Cs of tanzanite you can shop for the tanzanite jewelry in a smarter way.