Tanzanite's rich color can have depth comparable to the finest blue sapphire, with which it can be easily confused. Paler opaque Tanzanite has a delicate periwinkle color like the eyes of Elizabeth Taylor. It is supremely rare, coming from only one place in the world, the Merelani Hills of Tanzania, in the shadow of Mount Kilimanjaro. The source of its mesmerizing color is that Tanzanite is trichroic: that is, it shows different colors when viewed in different directions in stones of high clarity. One direction is blue, another purple, and another bronze, adding subtle depths to the color. Opaque tanzanite is available but it shows minimal the trichroic effect.

No gemstone discovered in East Africa has had greater impact on the modern world gemstone market than Tanzanite, a velvety blue variety of the mineral zoisite, first found in 1967, and named in honor of it’s country of origin by Tiffany & Co. in New York, who introduced the gemstone to the world in 1969.

According to popular local legend, a lightning strike near the Merelani hills set surrounding grasslands into an intense fire. When the Masai herders returned to the area with their livestock, magical blue stones appeared on the ground. A Portuguese geologist, named DeSouza, traveled to this area in Tanzania in the 1960's and noticed this magnificent blue stone. He brought it to the attention of Tiffany & Co. and introduced this exciting discovery to the world.

With vast deposits in the northern part of the country near the Merelani hills, Tanzania is the primary source of Tanzanite. It's also found in apparently limited deposits just across the border in Kenya. When heated to 600 degrees Celsius, dull brown to yellow zoisite undergoes an incredible metamorphosis, resulting in the creation of this vibrant blue to violet trichroic gemstone. All tanzanite is heated tanzanite, but heating does not diminish the investment value of this stone. All tanzanite is heat treated. Some eye-clear stones are available, but opaque tanzanites are a genuine investment if their inclusions are not intrusive, their color is outstanding, and they sparkle. Neither opaque not eye-clear stones have sharp inclusion lines. Such stones my be fakes or genuine tanzanite ruined by over heating. Investment genuine tanzanite will not display healed fractures like genuine natural rubies.

Lighting is the most critical factor when evaluating the trichroic transparent to translucent form of this gemstone. Tanzanite will display the most blue under natural light, while the violet or purple shades will be more apparent under incandescent light.

INDUSTRY NEWS

Tanzanite One, the Bermuda-registered company that acquired the tanzanite mines formerly controlled by South Africa-based AFGEM, will launch two separate ventures aimed at changing the way tanzanite was formerly bought and sold. Under the Preferred Supply Strategy, TanzaniteOne would sell its entire production to six contracted sightholders, who would be guaranteed three shipments of tanzanite, or sights, per year for the next six years. The identity of the sightholders was not revealed at the conference pending the finalization of their contracts.

"We're looking to work with companies that are looking to develop themselves within the tanzanite industry," TanzaniteOne Chief Executive , Michael Nunn, said at a recent conference. "We're looking for people to make the commitment to the tanzanite industry, who have the depth of understanding of where they want to be. We believe that, like the diamond industry, the tanzanite industry should be vertically integrated, and we are looking to our customers to do that where they can."

For sightholders, the advantage of the system will be a steady supply of tanzanite. Tanzanite is only found in one place in the world, the village of Mererani in northern Tanzania. With the exception of a sharp drop in prices following a media scandal in late 2001, tanzanite supply has been steadily decreasing — and prices rising — since the late 1990s. The mine tunnels in claims worked by small-scale Tanzanian miners are getting deeper, to the point where specialized equipment is required to work the mines, and the cost of mining tanzanite goes up again

Still, most of the world's tanzanite is produced by these small-scale miners and TanzaniteOne's market share is probably under 50%. TanzaniteOne supplements their production by buying from other miners.

If that's the case, then why — in the face of an uncertain market — would potential sightholders commit to buying from TanzaniteOne when tanzanite is available elsewhere with no long-term contracts? Independently from TanzaniteOne, wholesale dealers exhibiting in Tucson agreed that the scarcity of tanzanite is hurting the market. Some said they had decided to stop selling tanzanite altogether; there were other stones with a bigger market and steadier supply. To address the marketing issue, and to help support its sightholders, TanzaniteOne introduced another initiative: Tanzanite Foundation.

Conceived as a marketing and promotional body for the tanzanite industry, TanzaniteOne will be run by a London public relations firm. "We'd like it to be compared to the likes of the Platinum Guild," Nunn said. "It's not independent [from TanzaniteOne]; we're funding it, [and] we're the only company contracted to it financially." But rather than attempting to brand TanzaniteOne's gemstones, Tanzanite Foundation will simply promote tanzanite as a gemstone, for the benefit of anyone who sells it.

"It's not something we are looking to impose on the industry," Nunn continued. "It's something any individual member of the industry, if they feel it's a good cause, can embrace. If it achieves half of its objectives, we will have a much more stable industry."

Those objectives include promoting a grading system for tanzanite, developing public demand for tanzanite through "guerrilla marketing," and putting money back into the local community where tanzanite is mined, including the small-scale miners.

IDENTIFYING TANZANITE

In addition to the tendency for tanzanite to be trichroic, as explained above, tanzanite has a hardness of 6.5. It is blue to purple in color, with a white streak. The luster of tanzanite is vitreous and it is transparent to translucent. It has a specific gravity of 3.2 to 3.4. Tanzanite has good one directional cleavage and uneven to conchoidal fracture. Tanzanite occurs in several habits, including prismatic, striated, and columnar. Tanzanite looks different in different lighting situations. Sunlight usually makes it look more purple. Light bulbs and candlelight also bring out the purple and can make the grayish ones look brown. Fluorescent lights tend to bring out the blue more, as do overcast skies

Synthetic tanzanites have been advertised at lower prices. An excellent imitation was created in Russia, and this lab created gemstone is called fosterite. Recently a Massachusetts firm has been distributing a lab-created gemstone that simulates the color and look of tanzanite. This simulate, known as synthetic Fosterite, is grown in Russia and is worth significantly less than true tanzanite. Because this material may be mistaken for tanzanite, we recommend that you have any tanzanite or other precious gemstones that you purchase, evaluated by a qualified independent gemologist or laboratory.

Tanzanite, like many gems, is priced by carat weight. However, most importantly, tanzanite's price is determined by it's color. The more blue tanzanite is costly because, due the a blue color axis oriented along the width rather than the length of the crystals, more of the stone goes to waste when it is cut to bring out the blue. The blue is also more valuable because it resembles blue sapphire. The purple stones tend to resemble amethyst, making them less valuable. Tanzanite is a very delicate gem because of its low hardness and should not be used in everyday jewelry. Great care should be taken to ensure the stone will not be scratched or chipped. Tanzanite should not be cleaned with an ultrasonic cleaner because it could shatter; instead, use lukewarm water with a mild detergent to wash it then rinse with water the same temperature.

Tanzanite will be a combination of equal colors of blue and purple. Some lesser quality stones will only offer a dominate blue color. These are less valuable than the stones that offer a true tanzanite color combination of blue/purple. The intensity of these colors can vary due to light source under which it is viewed. There is also a reddish color that is the third color of tanzanite that your eye cannot see. A Chelsea Filter will show the third reddish brown color. Opaque tanzanite traditionally has commanded lower prices than the clear trichroic gemstones. However, as laboratory imitations hit the market, opaque gemstones have gained in popularity. Good quality opaque gemstones still display an intensive blue color, and are available in larger carat sizes that genuine trichroic tanzanite. Eternal Pearl always offers several examples of opaque tanzanites in large carat sizes and occasionally offers trichroic tanzanites in fine gold and silver jewelry as well.