Tanzanite

Lore & Background

In January 1967, Jumanne Mhero Ngoma stumbled upon sparkling blue stones at the Mererani hills; he received a certificate of recognition from President Julius Nyerere and a financial reward. Later that year, Manuel de Souza found transparent blue fragments and, after misidentification, samples were sent to the Gemological Institute of America, which correctly identified the mineral as zoisite. Henry B. Platt of Tiffany & Co. renamed it 'tanzanite' to market it effectively.

Reader's Guide

Tanzanite's significance lies in its single-source origin and unique optical properties. It is trichroic in its natural state, appearing blue, violet, and burgundy depending on crystal orientation, and changes color under different lighting—blue under fluorescent light, violet under incandescent. Most tanzanite is heat-treated to remove brownish hues, a process that is universal and does not affect price. The Tanzanian government has regulated mining through blocks and export bans to encourage local processing. Tanzanite remains a benchmark for rarity and color in the gem trade.

Did You Know?

• Tanzanite is only found in a mining area approximately 7 km long and 2 km wide near the Mererani Hills in Tanzania.
• The gemstone was named by Tiffany & Co. in 1968, as 'blue zoisite' was deemed not consumer-friendly.

Common Misconceptions (Editorial)

- Some believe tanzanite was discovered by Manuel de Souza, but the Tanzanian government recognized Jumanne Mhero Ngoma as the initial discoverer in January 1967. - It is often thought that tanzanite is a separate mineral; in fact, it is a blue and violet variety of the mineral zoisite, part of the epidote group.

Why It Matters (Editorial)

Tanzanite endures as a gemological marvel because it is found in only one tiny area on Earth—a 7 km by 2 km zone near the Mererani Hills—making it thousands of times rarer than diamonds. Its vivid trichroism, shifting from blue to violet depending on the angle, captivates collectors and jewelers alike, while its single-source origin ties its value and mystique directly to the landscape and history of Tanzania.