Color: Pale to saturated and intense blue to purplish blue
Gem Family: Tanzanite is a unique variety of the mineral zoisite.
Source: Tanzanite is mined only one place in the world: Merelani in Tanzania, in the shadow of Mount Kilimanjaro.
Clarity: Generally very transparent.
Size Range: 0.5 carat to 15 carats. The color of tanzanite is most intense in sizes above ten carats. Smaller tanzanites are usually lighter in color.
Shapes Available: Ovals, cushions, rounds, trillions, barion cuts and other shapes are available.
Enhancement: Virtually all tanzanite is heated from brown to blue. 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.
Lore & History: The name tanzanite is a tribute to this gem's only known source in Tanzania. Tanzanite was discovered in 1967 and named after the country of its birth by Tiffany & Co, 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.
Toughness & Hardness: The hardness of tanzanite is 5.5-6.0 on the Mohs scale, similar to opal.
Care & Cleaning: 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 without removing the gem because the stone could shatter in the heat of a torch. Try to avoid direct impact to the gemstone. Clean with warm water, mild soap, and a soft brush. Store separately from other jewelry and gemstones.
Special Characteristics: 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. Tanzanites which are blue tend to be more expensive than purpler ones 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.