“The most beautiful blue stone to be discovered in 2000 years”
– Tiffany & co 1968
Shortly after its discovery in 1967, Tiffany & Co. introduced Tanzanite to the world. In the middle of New York City, the slogan “in Tanzania and at Tiffany’s” turned the attention to a special feature only few gemstone can claim to possess.
Found in the foothills of Mount Kilimanjaro in eastern Africa, in an area called “the hills of Merelani”, it is the only known location of Tanzinite in the entire world.
a new horizon
Now, over 50 years later, another remarkable feature is emerging.
“For the past decades, when Tanzanite was pulled-up from the depths of the mine, it had a very distinct color. It is a mixture of brown, green, and greyish hues. To get the typical blue-violet appearance we all know as Tanzanite today, the gemstones are commonly heat treated.
But, over the years, as the mine in Tanzania went deeper and deeper into the Earth, the miners started to notice something peculiar. As they collected the gemstones, they noticed a select few of them were not grey, or brown, or green at all. No, some of them were naturally blue. This was something unheard of and is a recent development. The problem, however, was to distinguish scientifically, and reliably between a Tanzanite that received its color naturally and one who received its color through a heat treatment,” explains Alexander Kreis, Gemologist at KREIS.
A problem that is no more
Through technological advances, some gemological laboratories have started the certification process for natural, or “no heat” Tanzanites.
Most notably, the “German Gemological Association” (DGemG) in Idar-Oberstein.
“The process is just a couple years old and a coveted secret by the institutions who can perform this expertise. For the future, we expect Tanzanite to develop in a similar bifurcated fashion as Sapphires did. Meaning, that natural sapphires are more sought after, and thus a higher valued posession than their heat treated counterparts,” explains Gemologist Vanessa Kreis.
A new member of the collection
She continoues: “Natural Tanzanites occure few and far in between as is, and the color most of the time is somewhat weaker than the more common Tanzanite.”
However, in the second half of this year, KREIS was able to purchase an outstanding certified natural Tanzanite. Or as the laboratory writes: “No gemological evidence of heat”.
“Once again, this is highlighting the importance of contacts and reputation. We were very happy and thankful to have had the possibility to acquire a piece as remarkable as this one. The vivid blue color, towering size of 38.05ct, and astonishing clarity would already be enough to make it a special piece. But the fact that it is natural as well makes it one-of-a-kind,” says Stefan Kreis, Managing Director at KREIS.