Tanzanite is a variety of the crystal Zoisite, and is one of the rarest precious stones available in the market today. Tanzanite was discovered in the year 1967 and was first found in the Meralani Hills of northern Tanzania. Tanzanite is mined exclusively under permit from the Tanzanian government and unlike other precious stones like diamonds, Tanzanite is found only in Tanzania. Although Tanzanite is used for a variety of jewelry, one of the most popular applications of Tanzanite is Tanzanite rings. Tanzanite rings are available in a variety of finishes, and (like any precious stone) the cost of the rings varies depending on the size and quality of the stone.

Below is a list of properties that makes Tanzanite unique:

Trichroism

Tanzanite is unique in that its color varies depending on the angle of light (called Trichroism). A typical Tanzanite crystal can vary from sapphire blue, violet, to sage-green depending on crystal orientation, and one of the first things buyers look for in a Tanzanite ring is the Trichroism exhibited by Tanzanite. Unfortunately, not all Tanzanite crystals are deep blue in color and most jewelers treat the crystal with heat to achieve the desired coloration. The only problem with heat treated Tanzanite crystals is that they loose their natural Trichroism to a certain extent.

Rarity

Tanzanite is only found in certain areas of Tanzania, no other precious stone in the world can make such a claim. The Tanzanian government makes nearly $20 million annually from Tanzanite trade alone, and the resultant stones sell for close to $500 million in the jewelry market. Unfortunately, the rarity of Tanzanite has also fuelled speculation that its reserves might run out in the near future and there might not be another source of Tanzanite anywhere in the world. The rarity of Tanzanite has made it a sought after stone and a top quality Tanzanite gem can sell upwards of $500 per carat.

Exclusivity

Contrary to popular belief, there are restrictions on the amount of Tanzanite that can be mined in a year and only a handful of companies and organizations have been given permission to mine in Tanzania. In a nutshell, unlike diamonds and other precious gemstones there is a limited amount of Tanzanite mined every year making Tanzanite one of the most exclusive gemstones available today. As mentioned earlier, there is speculation that Tanzanite deposits are rapidly depleting and fresh Tanzanite might not be available forever.

Another factor that makes Tanzanite so special is that Tanzanite has a Mohs scale hardness of 6.5 (Diamond is a 10), making Tanzanite fragile when compared to other gemstones. It is not uncommon for Tanzanite to break on impact, and the relative softness of Tanzanite means that special attention has to be paid during the cutting and molding of raw Tanzanite crystals.

Like all precious stones the size and weight of Tanzanite is measured in carats and like diamonds, Tanzanite too has a clarity scale that determines the quality of the crystal after it is cut.

Grading of Tanzanite

Unlike diamonds, there is no single system in place for grading the quality of Tanzanite. One of the largest Tanzanite mining organizations, TanzaniteOne, has developed a grading system in collaboration with the Tanzanite Foundation that grades Tanzanite gemstones based on the saturation of blue violet and violet blue color. The saturation levels are given a rating from 1 to 10, and a rating of 1 indicates a Tanzanite gemstone with vivid exceptional colors (whereas 10 indicates pale colors). As mentioned earlier, there is no single standard when it comes to grading Tanzanite and world famous labs like GIA have a different grading scale for grading Tanzanite gemstones. In either case, it is important to understand the quality of the gemstone before buying Tanzanite.

Written by Richard M. Find the latest Tanzanite engagement rings as well as an authentic Tanzanite diamond ring.