Found in just one place on earth, tanzanite is a relatively recent discovery. Tiffany & Co named this blue-violet variety of zoisite in honor of Tanzania, where it was first unearthed in 1967. Because the crystals show different colors depending on the viewing direction, cutters can fashion gems with a range of color from violetish blue to bluish violet depending on how much weight they want to retain from the rough.
Merelani
Tanzanite has only one source: the hills of Merelani in northern Tanzania.
1967
Masai tribesman Ali Juuyawatu is credited with finding the first tanzanite crystal.
Pleochroic
Tilt tanzanite and you’ll see three distinct colors in three crystal directions.
Facts
- Mineral: Zoisite
- Chemistry: Ca2Al3(SiO4)3(OH)
- Color: Violet blue to bluish violet to violet purple
- Refractive Index: 1.691 to 1.700
- Birefringence: 0.008 to 0.013
- Specific Gravity: 3.35
- Mohs Hardness: 6 to 7