The gems were discovered in 2007 in the Mahenge region of south-central Tanzania. Their discovery alone has renewed the market for spinel with their translucent and high-value crystals.
To this day, Mahenge spinels remain among the most sought-after stones in the world of gemstones.
Now, the area produced an additional species. Blue cobalt spinels discovered in a nearby deposit last October are entering the market. They are said to be competing with the extremely rare vivid blue spinels from the Luc Yen region in northern Vietnam.
“Color-wise, blue is deeper, more saturated,” Wez Barber, managing director of Singapore-based Mahenge Gems, tells JCK. “It's less «neon» but more «electric». It's almost impossible, to capture on camera, like most stones. But in reality the colour is really unique and extremely striking.”.
At the recent JCK exhibition in Las Vegas, Mahenge Gems presented sophisticated specimens. The majority of them are approximately 1 carat in size.
“We've seen stones over 10 carats, but stones over 5 carats are extremely rare,” Barber says.
Visitors to the company's Gems booth were fascinated by them. “They were impressed by the possibility of large sizes, how pure the material is compared to Luc Yen. Of course, and the wonderful electric color that is unlike any other gemstone out there.”.
So says Sabrina Leong, head of marketing and PR at Mahenge Gems. She also adds that one client even considered cobalt spinel as an alternative to a blue diamond
Commercial pricing, according to Barber, starts around $2,000 per carat for a 1-carat stone of second-class color and clarity. And it exceeds $20,000 per carat for top color and clarity material in larger sizes.
However, as with all great gemstone finds, there is a caveat. “There's already a decline in supply,” says Barber. “It's only reaching us today at a small percentage compared to January this year. But even then, in January, there wasn't enough of this material.”.
