Tanzanite Buyer's Guidelines
Whenever you are buying Tanzanite you should make sure that it has been graded by an Independent Gemological Laboratory (not a laboratory controlled by the vendor) and comes with a certificate of authenticity which will provide information about the gemstone. As The Tanzanite Authority's North American member, all our Tanzanite Gemstones are conflict free and have been sourced in an ethical and legal manner complying with the Tanzanian Government's Minerals Act of 2010.
Grading Tanzanite gemstones considers the 4 C's like those used by The Gemological Institute of America. Generally, the higher the combination of these ratings, the more valuable the tanzanite. Our Tanzanite is perfect to make top quality jewelry.
Color - intensity of color and saturation of blue to violet
Clarity - description of natural flaws and inclusions
Cut - proportions and brilliance
Carat - a weight equivalent to 1/5 of a gram
Color or hue is the shade or tint referring to the blue in tanzanite and its degree of violet saturation in tanzanite color grading. The depth of color or tone is the relative lightness or darkness of a hue ranging from Intense to Faint by HKD Laboratories. The saturation is the strength (purity) of a hue and is considered by most gemological professionals to be the most important component in grading tanzanite color. The deeper the saturation color, the more valuable the tanzanite Tone/Saturation chart. Saturation is basically the depth of color in a stone, in essence the level to which color “fills” the stone. The more saturated a color is in a Tanzanite, the more valuable the gemstone. The best AAA Tanzanite has the finest color quality rating of Intense by HKD Laboratories - the GIA equivalent of vB6 and the Tanzanite Foundation’s rating of Exceptional . Be very careful of web sites or dealers claiming to be offering AAA investment grade tanzanite because many have lower grade gemstones. Any rating above AAA does not exist! There is an abundance of online Tanzanite marketers showing a plethora of "A's" and or "+ signs" like AAAA, vB6++ or AAAA++ etc. in an attempt to brand their gemstones more marketable despite the fact that the color is certainly nowhere close to the true finest grades. It is nothing more than a marketing gimmick. Insist on a non-affiliated 3rd party certification as to the color and clarity of a Tanzanite gemstone you're considering. Less than 1% of all Tanzanite production is true intense AAA quality and it is considered exceptionally rare. For a colored stone (any gem other than diamond), color is the most important factor in determining quality. The finest and deepest colors of Tanzanite are usually seen in gemstone sizes over 5 carats according to the Gemological Institute of America, or GIA the world’s foremost authority on colored gemstones. Please be aware that images on any web site including this one can not always reflect the true color/brilliance of Tanzanite or most any other gemstone.
Color range examples. Here is an average gemstone vs Top AAA Color.
GIA color guidance chart.
Clarity refers to any natural flaws and inclusions in a tanzanite. Tanzanite's clarity category ranges from Flawless to Heavily Included. Tanzanite described as Eye Clean or Slightly Included may contain minor inclusions that can only be viewed through a jeweler's magnifying loupe, which magnifies the Tanzanite by ten times. Such inclusions do not detract from the perfection of the gem to the unaided eye. Tanzanite described as Moderately Included and Heavily Included contain inclusions that can be seen with the unaided eye. The more flawless the faceted Tanzanite, the more valuable it is. Top quality Tanzanite should be at least eyeclean but preferably loupeclean as well. Once again, a third party certification will eliminate any doubts. Investment grade Tanzanite should be loupeclean. These charts show the clarity rating for diamonds and then GIA's clarity rating for Tanzanite gemstones.
Cut refers to the proportion and brilliance of a faceted tanzanite. A very good cut ensures that the stone's facets reflect light to create maximum brilliance. If tanzanite is cut too deep or too shallow, its radiance will deflect through the sides from the bottom of the stone, detracting from its brilliance. The more precise the craftsman's cutting, the more valuable the tanzanite. In attempting to quantify tanzanite's proportions, reference is often made to depth percentage. This is calculated by taking the depth and dividing it by the girdle diameter (or average diameter, in the case of non-round stones). The acceptable range is generally 60–80%.The cut has the least impact on value of the 4 C's but is still important. Tanzanite of the same carat weight, color and clarity can have differing values based on the cut because of the amount of raw material needed to make the cut.
Carat is the term used to measure a tanzanite's weight. One carat is 100 points and weighs 1/5 of a gram. Two seemingly identical tanzanite will have different carat weights if they vary in depth called the pavilion. Carat weight affects the price generally as weight increases stones in the same quality bracket will cost more per carat.
We recommend that the purchase of a loose faceted tanzanite or tanzanite jewelry piece is accompanied by a certification from HKD Laboratories Ltd. (or other qualified laboratory's certificate like GIA or ICGA), detailing the specifics of the gemstone. This is the buyer's guarantee that the tanzanite is authentic and has been graded in accordance with the an Independent Gemological Laboratory - not a laboratory controlled by the vendor or dealer. We also recommend a no questions asked 100% refund policy after an inspection period. Tanzanite Americais is honest and reputable offering both.(Click on image to enlarge)
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