The Origin & Allure of Tanzanite
The Discovery of Tanzanite
In 1967, one of the most extraordinary gemstone discoveries was made in the Merelani Hills near Arusha, Tanzania, under the shadow of Africa's tallest peak, Mount Kilimanjaro. This rare gem, later known as Tanzanite, was found deep beneath the earth by a local Maasai tribesman named Ali Juuyawatu, although some accounts credit Manuel d'Souza, a tailor and part-time prospector, with the discovery after being led to the area by the Maasai tribesman.
The Naming of Tanzanite
Traditionally, the discoverer of a gemstone gets the privilege of naming it, often adding ‘ITE’ to the end of a word to create a fitting name, such as “Ifounditite.” However, in this case, the gemstone was later named "Tanzanite" by Tiffany & Co., in 1968, a year after its discovery. Tiffany & Co. recognized Tanzanite's commercial potential as a rival to the reign of sapphires and introduced it to the global market. Today, Tanzanite is considered one of the rarest gemstones in the world, estimated to be 1,000 times rarer than diamonds and 100 times rarer than sapphires.
What Makes Tanzanite Special?
Tanzanite is a variety of the mineral zoisite, a calcium aluminum hydroxyl sorosilicate. It derives its name from Tanzania, the only place on earth where it is found. This gemstone is highly prized for its vivid colors, ranging from deep blue to violet, along with an array of fancy colors. Tanzanite is trichroic, meaning it displays different colors when viewed from different angles, especially along the A, B, and C axes of the rough crystal.
The Role of Heat Treatment
One fascinating aspect of Tanzanite is the use of heat treatment to enhance its color. The process involves heating the stone to around 500-600 degrees Celsius, converting its brown, yellow, gray, and even green hues into the vibrant blue and violet shades that Tanzanite is known for. Today, the vast majority of Tanzanite on the market is heat-treated, although some stones naturally emerge from the earth with rich blue-violet coloring. Interestingly, when heated, the trichroic stone often becomes dichroic, losing one of its visible colors. This heat treatment was initially employed to rival sapphires in the market, making Tanzanite more desirable.
A Changing Perspective on Tanzanite
It’s important to note that Tanzanite was not always heat-treated. When it was first discovered, some stones were naturally blue or violet. However, as the more vibrant material became scarce, much of the mined material was brown or greenish, which was less desirable in the gemstone market at the time.
As with many industries, narratives and views must evolve. Some might argue that calling these multicolored, unheated wonders "Tanzanite" instead of "fancy zoisite" is a marketing strategy. However, we believe that a stone should not have to be heat-treated to be considered Tanzanite. To dismiss the naturally occurring colors and only regard the heated, blue-violet stones as true Tanzanite takes away from the gemstone’s rich heritage, named after its country of origin.
Conclusion: Embracing Tanzanite in All Its Forms
In our humble professional opinion, Tanzanite's true value lies in its diversity, and every variation of this remarkable gem should be celebrated for what it is—a rare and beautiful gift from the earth.