Tanzanite blue purple

Tanzanite is one of the rarest gemstones in the world, known for its deep blue-violet color and found only in Tanzania.

About this subject

Tanzanite is a blue-violet variety of the mineral zoisite, discovered in 1967 in the Merelani Hills, near Mount Kilimanjaro, Tanzania. Its stunning color, ranging from sapphire blue to intense violet, is due to the presence of vanadium. As a relatively young gemstone, it gained rapid popularity after Tiffany & Co. launched it internationally in the 1960s.

The gem is known for its strong pleochroism, displaying different colors from different angles: blue, violet, and brownish red. Most tanzanites are heat-treated to achieve the prized blue-violet hue. Its hardness on the Mohs scale is 6.5 to 7, making it suitable for jewelry but requiring care to avoid scratches.

Tanzanite is considered a thousand times rarer than diamond, occurring in an area only 7 kilometers long and 2 kilometers wide. In 2020, the Tanzanian government built a wall around the mine to control extraction and smuggling. The gem is extracted mainly through artisanal and industrial mining, with significant sustainability challenges.

Interestingly, tanzanite is a December birthstone in some modern lists, and is believed to promote emotional and spiritual balance. Its value has increased significantly over the years, with high-quality specimens exceeding US$1,000 per carat.

Frequently Asked Questions

Where is tanzanite found?

Tanzanite is found exclusively in the Merelani region of northern Tanzania, near Mount Kilimanjaro. No significant commercial deposits exist anywhere else in the world.

Does tanzanite undergo any treatment?

Yes, most tanzanites are heat-treated at low temperatures (around 400 to 600°C) to enhance the blue-violet color, removing unwanted brownish tones.

How durable is tanzanite for jewelry use?

With a hardness of 6.5 to 7 on the Mohs scale, tanzanite is moderately durable but can be scratched by harder materials like quartz or topaz. Avoid strong impacts and use protective settings for rings.