The gemstone discoveries in East Africa in the 1960s
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 lifetimes.
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.
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 bluer 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 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.