Glittering purple to blue pebbles were picked up by the members of their tribe, who were curious as to how these sapphire-like stones suddenly appeared.
Tanzanite, is a variety of zoisite that had fairly recently skyrocketed in popularity by serving as a mid-to-high end alternative for blue sapphire. The zoisite specimens that crystallize in gem-quality clarities are often brown and unappealing, however with exposure to certain degrees of heat, they can turn anywhere from a deep burgundy red to a violetish blue.
Henry B. Platt, the great grandson of Louis Comfort Tiffany (Tiffany & Co.) coined the variety as 'Tanzanite', naming it after its origin source. Together with Walter Hoving, he launched it at Tiffany's in October of 1968. The stone's popularity was boosted by an international recognition sponsored by the jewelry behemoth, and tanzanite quickly became known as a precious gemstone in the modern world.
In comparison to blue sapphire, tanzanite tends to possess a stronger purple or violet modifying hue, so pure-blue stones can command exceptional prices. The gemological properties are also very far off from corundum's, with a Moh's scale hardness of only 6-6.5 (sapphire corundum's is 9).
Throughout the years, tanzanite had only one main source, that original area in Merelani, Tanzania near Mt. Kilimanjaro, where Tiffany & Co. and its partners set up Tanzanite One, the premier mining operation for the gem variety.
Today, several other smaller-scale sources have been discovered, aiding to supply the widespread demand for this brilliant blue gemstone. Tanzanite's rise to fame in the recent decades, has been a little bit rocky- with previous supply levels being frustratingly inconsistent due to the limited producers. The trade however, persevered in its belief of the stone and continued to market it to the general public until more sources were found.
While tanzanite may have a luster that is slightly shy of sapphire's, its deep blue colors can more than rival the blue stone's beauty and allure.
It should be assumed that all tanzanite on today's market has been heated at least in some way. Specimens may require different types or degrees of heating, but the variety itself is generally accepted to be produced by heat treatment.
Blue to purple tanzanite can exist in nature, heated by natural geological occurrences, but these are very rare, and hard to tell apart. The trade generally accepts tanzanite as it is, often without further mention of the heating procedures, as they are a staple for the stone's production in almost all situations.
2018 marks the 51st anniversary of Tanzanite as a precious gemstone.
