Chemical Composition and Formation Process

Tanzanite is a blue-violet variety of the mineral zoisite, a calcium aluminum silicate with the chemical formula Ca₂Al₃(SiO₄)₃(OH). It forms under unique conditions of high heat and pressure in the presence of vanadium, which is the trace element responsible for its distinctive blue to violet coloration. Tanzanite is only found in a small area near the Merelani Hills in northern Tanzania, near Mount Kilimanjaro.


The name “Tanzanite” was coined by Tiffany & Co. in 1967, shortly after the gem’s discovery, to highlight its origin in Tanzania. Prior to this, it was known simply as “blue zoisite.” Alternative names include “blue zoisite” and “safir de Tanzanie,” reflecting its blue color and origin.

Electric Cosmology

According to Maasai legend, tanzanite was first discovered after a lightning strike set the surrounding hills on fire. The heat from the fire transformed the brown zoisite crystals into vibrant blue stones, believed to be a gift from the gods.

Mining, Production and Use

Discovered in 1967 by Manuel de Souza, a local prospector, the gemstone was rapidly commercialized with the help of Tiffany & Co., which brought global attention to this unique gemstone.
Tanzanite is mined exclusively in a small area of Tanzania, making it one of the rarest gemstones in the world. Mining operations are mostly concentrated in a 20 square kilometer area near the Merelani Hills. The mining process involves both artisanal and large-scale industrial mining methods. Artisanal miners often work in difficult conditions, manually extracting the stones from narrow, deep tunnels.

Once mined, tanzanite undergoes a heating process to enhance its color. The natural brownish crystals are heated to 600 degrees Celsius to achieve the deep blue and violet hues that are most prized.