Why is Tanzanite so special, and what are the origins of this precious gemstone? Tanzanite is special because it not only comes from the blue and violet variety of a mineral called 'zoisite' . And its only source is in the hills of Merelani near majestic Mount Kilamanjaro in Northern Tanzania. Tiffany & Co named this gemstone in honor of Tanzania, where it was first discovered in 1967. I am selling a Sterling silver Tanzanite ring bought at auction, with a weight of 2 grams, a size P and markings 925. Has a basket style mount.