The story of Tanzanite began not all that long ago. It was discovered by Masai tribesman Ali Juuyawatu of Merelani Hills, Tanzania, in 1967, and it hit the market in 1968. Tiffany and Co was responsible for popularizing the stone with a large international campaign, but its allure is far more than just publicity.
Tanzanite is a gem variety of the mineral zoisite. It is notable for its striking pleochroism, which is a change in a gem’s color depending on the angle at which it is viewed. Pleochroism is a phenomenon not commonly seen in most gems, and the uniquely vibrant display that we observe in Tanzanite is truly unlike any other stone.
Tanzanite crystal exhibiting pleochroism; Image by Michael C. Roarke via Mindat
The vast majority of Tanzanites on the today’s market are heated to enhance their color. While some stones such as sapphires are subjected to temperatures up to 2000°C, Tanzanite is treated in gentler conditions ranging from 500 to 800°C. This treatment allows trace amounts of vanadium within the stones molecular structure to change into a state that produces a range of striking violet-blue hues.
A 16.57ct faceted Tanzanite before and after heat treatment next to the rough it was cut from; Image by Orasa Weldon via GIA
2.44ct Heat treated Tanzanite; Image by Skyjems
As its name suggests, this gem originates from only one deposit in Tanzania. The area of mining measures only 20 square kilometers, and experts estimate that the source will be completely depleted within the next 10 to 12 years. This limited availability of Tanzanite makes high quality stones extremely rare and difficult to find in most retail settings.
Another factor of Tanzanite’s allure is its high refractive index (RI). Refractive index describes a gem’s ability to bend and alter light. Stones with higher RIs are capable of taking on a higher polish and exhibit excellent brilliance. With an RI of 1.7, Tanzanite is an unquestionably good contender for jewelry with exceptional bling factor. For comparison, the RI of sapphire is 1.76.
Exceptional brilliance is demonstrated in this 2.83ct cushion cut Tanzanite; Image by Skyjems
Since Tanzanite has a slightly lower hardness than some other stones, special care is required when designing and creating jewelry with it. Here at Skyjems, we have the experience and attention to detail required to bring your ideas to life! Here are some examples of designs featuring Tanzanite that we have made in the past.
3.08ct Tanzanite and White Sapphire Ring set in 14K Rose Gold
Tanzanite and White Sapphire Ring in 10K White Gold
Tanzanite Earrings in 14K White Gold
Tanzanite and Diamond Pendant in 14K Yellow Gold
Tanzanite is a truly under-utilized gem in the world of jewelry. Ready to create a one-of-a-kind piece with this show-stopping stone? Let us help you create the jewelry of your dreams! Contact us today to get started.