Introduction
Tanzanite was discovered in East Africa in the 1960s. This discovery transformed the jewelry world: new varieties, new colors, and new variations on existing species made that decade the most exciting time in the gemstone industry in our century.

But no gemstone discovered in East Africa has had more of an impact on the world gemstone market than tanzanite, a velvety blue variety of the mineral zoisite that was found for the first time in 1967 and named after the country of its birth by Tiffany & Co in New York, who introduced the gemstone to the world market in 1969.

Tanzanite is the ultimate prize of a gem safari. Its rich purples and blues often have a depth comparable to the finest sapphire. Paler 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.

New mining techniques and the liberalization of the Tanzanian economy has helped to boost production in the past few years to make tanzanite more available than ever before in the history of the gemstone.

The source of its mesmerizing color is that tanzanite is trichroic: that is, it shows different colors when viewed in different directions. One direction is blue, another purple, and another bronze, adding subtle depths to the color. When tanzanite is found in the ground, the bronze color dominates. However, with gentle heating, the cutter can watch the blue color bloom and deepen in the stone.

Legend has it that the affect of heat was first discovered when some brown zoisite crystals laying on the ground with other rocks were caught in a fire set by lightning that swept through the grass covered Merelani hills northeast of Arusha. The Masai herders who drive cattle in the area noticed the beautiful blue color and picked the crystals up, becoming the first tanzanite collectors.

The color of tanzanite is most intense in sizes above ten carats. Smaller tanzanites are usually paler in color. Tanzanites which are more blue rather than purple tend to be more expensive because the crystals tend to form with the blue color axis oriented along the width of the crystal instead of the length. That means that if the cutter chooses to maximize the purity of the blue color, the stone cut from the rough will be smaller and will cost more per carat. The blue color, however, is so beautiful, that the sacrifice is often worth it.

Tanzanite jewelry is a little more delicate than other gemstone jewelry and should not be set in a ring that will be worn during strenuous activity. Never clean tanzanite in an ultrasonic cleaner or resize or repair a ring set with tanzanite because the stone could shatter in the heat of a torch. It is available in a variety of shapes and sometimes in large sizes that are perfect for an important necklace.

Definition
Tanzanite (Tanozanoite ): Tanzanite, possessing what is considered to be the optimum blue of any gemstone, can leave even the best sapphires lacking. However, most Tanzanite occurs naturally as a transparent brown or green crystal, colored by vanadium. This material is routinely heat treated to temperatures of approximately 500 degrees, turning it light to dark violet, blue and bluish purple.

Tanzanite displays strong trichroism, which means it displays three different colors from different directions: blue from some, purple from others, you may also see flashes of red, green, yellow, orange, or brown. Tanzanite is also extremely sensitive to different light sources, changing color to the violet end of its spectrum under incandescent light: better quality specimens will remain an intense blue under all light. Clarity in Tanzanite is generally clean to standard eye-clean gems.

Because it is found in quite large sizes, gems of hundreds of carats are in existence, Tanzanite can be cut into almost all shapes. The most popular sizes are less than 20 carats in ovals and cushion cuts; rounds are also popular, as are other cuts such as emerald and trillion. Tanzanite is a variety of Zoisite, a hydrated calcium aluminum silicate, possessing a hardness of 6.5 to 7 on the Moh's hardness scale with a perfect cleavage. The cleavage can make Tanzanite brittle so it should be worn with care.

Tanzanite's principal, and only official source, is from a five-mile square hilltop in the Merelani Hills, in northern Tanzania. Although Tanzanite was only officially recognized in 1967, it became so well known that in 2002, by decree of the American Gem Trade Association (AGTA), it became one of the birthstones for the month of December alongside zircon and turquoise.

Color Facts
Tanzanite possessing what is considered to be the optimum blue of any gemstone can leave even the best sapphires lacking. However, most Tanzanite occurs naturally as a transparent brown or green crystal, colored by vanadium. This material is routinely heat treated to temperatures of approximately 500 degrees, turning it light to dark violet, blue and bluish purple

Tanzanite displays strong trichroicism, which means it displays three different colors from different directions: blue from some, purple from others, you may also see flashes of red, green, yellow, orange, or brown. It is also extremely sensitive to different light sources, changing color to the violet end of its spectrum under incandescent light: better quality specimens will remain an intense blue under all light.

Color Tips
Before making a purchase considering a Tanzanite's color is pivotal to the process of evaluation, a Tanzanite's clarity comes second. Taste in color is a personal matter, so while the following points are verified facts from the gemstone world they are also up for contention, and in no way are intended to restrict your personal preferences.

Some think that when buying a Tanzanite, as a gem alone or set into jewelry, the darker the color the better the gem: False. If a Tanzanite is too dark and subdued it's lifeless, lacking all the qualities for which it is renowned. Go for rich, bright, vivid colors: with clear medium-tones. The highest premiums are commanded by colors that vary from blue to violet blue, the most popular being a highly saturated blue. Some Tanzanite also has a strong purple coloration looking slightly amethyst like, these are much cheaper but non-the-less are extremely beautiful.

The more intense the color the higher the price, and prices for large top quality Tanzanite can be quite expensive. Of all gemstones Tanzanite's prices rise and fall like no other, due in part to the irregularity of production from the mines. Prices of very fine Tanzanite gems of top color in large sizes, can reach as much as $1000 per carat retail. So if your budget doesn't allow it look for muted colors, colors between hues, which are still appealing but less expensive.

An important point to keep in mind when buying Tanzanite is that its trichroic in nature: changing colors through the blue spectrum under different light sources. This is not to be confused with the dramatic color-change effect seen in Alexandrite and some Sapphire where the gems change colors completely. To get indication of these properties examine Tanzanite under different lighting, natural, artificial and subdued lighting.

In the early morning and late afternoon light Tanzanite may gain some red or orange coloration making it slightly purple. The best time to look at a Tanzanite is under the noon sun, where the color is neutral showing the true color. The bluer the Tanzanite the better, and usually more expensive too!

Tanzanite Care
Remove jewelry before doing heavy work. Take care of your Tanzanite by treating it gently, and by keeping your gems and jewelry clean.

To keep your gems sparkling, clean them when dust and fingerprints have dimmed their brilliance. The best way to clean your gemstone jewelry is in a bowl of water with a few drops of ordinary dish detergent. Using an old toothbrush or other soft brush, scrub gently behind the stone where dust and soap can collect. Dry your jewelry thoroughly with a soft cloth, and use 'Q tips' to get into the more difficult places.

Soaking Tanzanite in alcohol, vodka, overnight loosens stubborn dirt, which can then be rinsed and brushed away. Always use a soft brush but no abrasives, not even toothpaste; such abrasives will not hurt Tanzanite but will scratch the softer silver, gold or platinum settings.

In the case of Tanzanite, possessing a medium hardness of 6.5 to 7 on the Moh's hardness scale with perfect cleavage, home ultrasonic cleaners should not be used. Ultrasonic cleaners can be used to clean lightly included sapphire, ruby, diamond, amethyst, citrine, garnets, iolite, chrysoberyl, and unadorned jewelry but it may damage gems like emerald, pink tourmaline, pearls, coral, lapis lazuli, malachite, turquoise, and any gem that has many inclusions. When in doubt, don't use it, and as always consult a local reputable jeweler before attempting any cleaning yourself.

To protect the beauty of your gems and jewelry, make sure you store each piece separately. Gems may scratch each other or the metal in your jewelry. Avoid creating a tangle of jewelry by wrapping each piece individually or keeping it in its own compartment. Especially when you travel, make sure your jewelry pieces don't jostle each other in one bag.

Gemstones are among the most durable of nature's creations. With a little care, they will be as beautiful for generations to come as they are today.