10 Interesting Facts About Tanzanite

Tanzanite is a relatively new arrival in the gemstone world, but it has quickly become one of the most sought-after and intriguing gems available today. With its captivating colours and one-of-a-kind origin, tanzanite has enchanted jewellers and collectors alike.

Discovered only in the 20th century, this vivid blue-violet gem has a story packed with rarity, marketing genius, and dazzling optical effects. Here are ten interesting facts about tanzanite that reveal just how special it really is.

Tanzanite Is Only Found in One Place on Earth

Unlike many gemstones which can be found across multiple continents, tanzanite comes from just one location, a small mining area at the foothills of Mount Kilimanjaro in Tanzania. The entire known deposit measures just 7km long and 2km wide. This extremely limited source has earned tanzanite a reputation as a "one-generation gemstone," with speculation that it may be mined out within our lifetime.

It Was Only Discovered in 1967

Tanzanite was first discovered in 1967 by a local Masai herdsman. He stumbled across some vivid blue crystals exposed by a lightning-induced fire. Geologists later identified the crystals as a previously unknown gem-quality variety of zoisite, and the rest, as they say, is history.

Tiffany & Co. Gave Tanzanite Its Name

When Tiffany & Co. introduced the gem to the international market in 1968, they wisely decided that "blue zoisite" sounded too much like "blue suicide", not exactly the best name for sales. Instead, they named it tanzanite, after its country of origin, and launched a marketing campaign that catapulted it to instant fame.

Tanzanite Is 1,000 Times Rarer Than Diamond

Thanks to its single-source origin and finite supply, tanzanite is considered up to 1,000 times rarer than diamond. Despite this, it remains more affordable than many traditional precious stones, a fact that only adds to its appeal among collectors and jewellery designers.

It's a Variety of Zoisite

Tanzanite is the striking blue-to-violet variety of the mineral zoisite, which also occurs in earthy tones like green, pink, and brown. It's the only variety of zoisite ever used in fine jewellery, thanks to its exceptional colour and transparency, although you can often find an opaque green ziosite with patches of ruby in it (also known as anyolite) that has been cut into beads or cabochons for jewellery making.

Most Tanzanite Is Heat-Treated

Nearly all tanzanite on the market has been heat-treated to improve its colour. In its natural state, tanzanite often displays a brownish or greenish tone. Gentle heating brings out the stone’s signature blue and violet, permanently enhancing its beauty.

It’s Often Cut into Ovals, Cushions or Emerald Shapes

Tanzanite’s crystals naturally form in elongated prismatic shapes, which makes it especially well-suited to oval, cushion, and emerald cuts. These shapes help maximise colour and minimise waste, perfect for a gem as rare and precious as this.

High-Quality Tanzanite Can Show Flashes of Pink and Red

Under certain lighting conditions, some of the finest tanzanites reveal fleeting flashes of pink or red. These fiery highlights are caused by the gem’s trichroic nature and are considered a sign of exceptional quality.

Masai Lore Says It Came from the Sky

According to local legend, tanzanite was created when lightning struck the ground, setting fire to the surrounding land and transforming ordinary stones into shimmering blue crystals. This belief gives the gem an almost mythical origin story, despite its recent discovery.

The Largest Faceted Tanzanite Weighs Over 700 Carats

The largest known faceted tanzanite is the "Queen of Kilimanjaro," a remarkable 737.81 carat stone set into a tiara alongside diamonds and tsavorites. This incredible gem not only highlights the potential size of tanzanite crystals, but also serves as a tribute to its royal appeal.

Whether you’re drawn to its vibrant colours, its rarity, or its modern-day origin story, tanzanite offers something truly unique in the world of gemstones. It may be a newcomer compared to ancient gems, but in just a few decades, tanzanite has more than earned its place among the greats.