- Tampa Bay Times
By the 1960s, many gemologists thought they had seen everything – only to be surprised by the discovery in Tanzania (hence its name) of an exciting “new” gemstone.
The year was 1967. At first glance, Manuel d’Souza, a Portuguese prospector, thought he had found a new species of sapphire – but these blue stones turned out to be something else entirely. H e quickly joined forces with Tiffany & Co., who became the sole distributor of this product and started a million-dollar publicity campaign to build excitement. In fact, many of the early, signed Tiffany tanzanites are some of the most beautiful examples you’ll find. These rare, signed versions can be worth $15,000 to $30,000 in the largest sizes.
1. Tanzanite is really a version of zoisite, a gemstone that was first identified in 1805. What makes this zoisite special and deserving of its own name is that the zoisite found in Tanzania is high in vanadium, and when heated becomes a rich, intense blue.
2. Tanzanite is trichroic, which means it breaks up light into three directions. This is why it takes on different shades when viewed from different directions.
3. Tanzanite is one of the softer gems and needs gentle wear and care.
4. Millions of carats have been mined, heated and sold in various degrees of color and clarity. Most have been lower quality, but even some of the best do not hold their retail value well. Regardless, they are still highly popular and always collectible in the deeper and more intense blues.
Today, overmining of tanzanite has produced a glut on the market that has hurt the resale value of the more common, less-vibrant examples. The Tiffany & Co. tanzanite ring has a retail value of $30,000 -$35,000 and a fair market value of $10,000 - $15,000 . The smaller Levian ring has a retail value of $1,800 and a fair market value of $400-$600.