Tanzanite is noted as a very extraordinary gemstone, because not only is it beautiful, but it is sought in only one place worldwide. Found in East African,
specifically near Arusha in the Merelini Hills, to this day, the search is still carried out for this gemstone. Small mines use modern methods to try and extract the Tanzanite from the earth.
Tanzanite is a variety of the zoisite mineral and reflects beautiful colors of bluish-purples. Made up of calcium aluminum hydroxyl silicate, this gemstone was named from its first discovery within the rolling hills of northern Tanzania, hence its name. Millions of years, long ago, on a vast plain shadowed by Kilimanjaro gneisses, metamorphic schists, and quartzites were mixed together to form this isolated mountain. It was here that several thousands of years later, Tanzanite would be discovered within.
This crystalline gemstone contains the presence of vanadium which is a grayish-silver colored metal type chemical that is soft in texture, and along with other conditions present within its specific geological environment, this makes the gemstone quite rare. The structure of this crystal is orthorhombic which relates to its crystalline structure and its unequal right angle axes. It is also trichroic, meaning it gives off three different colors.
When it comes to hardness of Tanzanite, you will find this gemstone sitting on the Mohs scale with a hardness of 6.5. While not as hard as the diamond or a sapphire, it has more in common with an emerald, but is not quite as brittle. On another note, it is still harder than steel, which is rated at about a 4 to 5 range. In regards to the system of grading Tanzanite, it is just like other semi precious gem and is only graded by each independent gemological grading laboratory. However, the Tanzanite that gives off that intense color of violet blue means that it is a very top grade.
Oddly enough, loose tanzanite gems are far rarer than even a diamond, specifically, one thousand more times rare. Since it is softer in nature, many pieces are often destroyed by accident. It has also been predicted that all Tanzanite will be completely exhausted in about 10 to 15 years. It is because of this, that this rare gemstone is considered to be an investment when purchased.
As a product of intense research, it has also been found that it is unlikely for Tanzanite to ever be found in a different area, or another area of the world. This is because it was created by some phenomenon, which geographically provided conditions which will never exist again.