Tanzanite: Sapphire Look-Alike |
The scarcity of tanzanite makes it one of the most desirable and sought-after gemstones in the world. The only place it exists is in Tanzania in East Africa, and thanks to Tiffany Jewelers in New York, it was named and brought to public attention after it was discovered in 1967. For many years Tiffany's had sole rights to it. Its crystals of a deep blue were discovered in the Merelani Hills. The crystals were unknown and not noticeable until spotted by Masai shepherds who saw their sparkle. When finally harvested they were thought to be sapphire crystals.
Tanzanite is a variety of the mineral Zoisite and occurs naturally in blue, green, yellow, pink, and usually brown,. Zoisite was first discovered in 1805 by an Austrian Baron and it was named after him. It comprises a complex group of minerals which do not grade into more common varieties. It has a glassy finish, and a hardness of 6 according to the Mohl's scale of hardness. It occurs in the metamorphic rocks in New England, mostly as gray crystals in quartz veins. Light colored varieties of zoisite become blue after a second heating after being touched with a drop of cobalt blue.
The fluorescent pink ones are found in North Carolina and brown ones in Ducktown, Tennessee. Green zoisite is located near Sulphur Bank in California. The find in Africa of the transparent dazzling tanzanite was a late and completely unforeseen wonder which has been tirelessly promoted into popularity.
The tanzanite crystals had grown in elevations beginning millions of years ago on a flat stretch of land in the shadow of Mount Kilimanjoro, and their final discovery caused much excitement among collectors and jewelry lovers all over the world. The excitement continues today. There ia a variety of prices charged for tanzanite, most on the high end since it is such an exclusive gemstone. It is cut in any shape the designer can come up with, plus the usual classic shape. Buyers feel it underlines the individuality of the wearer who feels confident and self-assured just for having such a unique and beautiful gem..
The tanzanite crystals are heat-treated to achieve a sapphire blue color, plus lavender and blue/ violet, all of which are prized. The colors range from an ultramarine blue to a light lavender blue, with a blue with a hint of purple being the most coveted. Depending upon the angle, the tanzanite reflects different colors. Cutting the stone can be very difficult as its cleavage is prominent in only one direction, and any heat treatment is performed with extreme care so as not to ruin the stone.