Tanzanite: The Rare Blue-Violet Gemstone from Tanzania

Tanzanite is famous for its striking blue-violet color, and it's become one of the most recognizable colored gemstones around today. It's a relatively new discovery, but it didn't take long to catch the world's attention — jewelers and collectors alike were quickly drawn to it, and many now consider it second only to Sapphire in popularity among colored gems.

Part of what makes Tanzanite so special is just how rare it is. While many gemstones can be found in multiple places around the world, Tanzanite comes from a single small area near Mount Kilimanjaro in Tanzania — nowhere else. That narrow source is a big reason it's considered even rarer than Diamonds.

The Discovery of Tanzanite

Unlike gemstones that have been prized for thousands of years, Tanzanite has no ancient mythology behind it. Its story only begins in the twentieth century — but in that short time, its discovery and striking color have already built up a history all their own.

Mineralogically speaking, Tanzanite is actually a variety of Zoisite, a mineral named after Baron Sigmund Zois, a Slovenian nobleman and mineral collector. Zoisite itself was nothing new — it had long been known in shades of green and opaque pink, and was even used in jewellery from time to time. But it had never really made a name for itself as a gemstone.

That changed in 1967, when blue-to-violet Zoisite turned up in the Merelani region of Tanzania, near Mount Kilimanjaro.

Who actually discovered it first is still a bit of a mystery, and a few different names come up in the story. The most commonly told version involves a local tribesman, Ali Juuyawatu, who is said to have stumbled upon a translucent blue crystal near the foot of Kilimanjaro. He brought it to Manuel D'Souza, a prospector working in the area at the time.

D'Souza had actually been on the hunt for Rubies, and his first guess was that the blue crystals were Sapphires. But once he looked closer, it turned out the mineral composition didn't match — these were something else entirely, not Sapphire at all.

Another key figure in the story is Scottish geologist Campbell R. Bridges, who would later become known for discovering Tsavorite in Tanzania. Bridges played a part in identifying the new gem early on and helping introduce it to the world, and samples eventually made their way to the United States, where the Gemological Institute of America (GIA) examined them.

Tiffany & Co.: From Blue Zoisite to Tanzanite

It didn't take long for this newly discovered gemstone to catch the eye of the American jewellery industry — Tiffany & Co. in particular.

Henry B. Platt, a member of the Tiffany family who would go on to serve as the company's President and Chairman, was especially taken with its remarkable color. There was just one problem: its mineralogical name wasn't exactly jewellery-friendly. Said aloud, "blue Zoisite" sounds a little too close to "blue suicide" for comfort — not the kind of association you want when introducing a new gem to consumers.

So a new name was chosen instead: Tanzanite, a nod to Tanzania, the country where the stone had been found.

In 1968, Tiffany & Co. officially launched Tanzanite in the American market, promoting it as an exciting new blue gemstone from Africa. The campaign put Tanzanite on the map internationally, and its reputation within the jewellery world grew fast from there.

With its striking mix of blue and violet, Tanzanite quickly established itself as one of the important colored gemstones of the modern era. Demand kept climbing, and by 1998 and 1999 it was reportedly among the best-selling colored gemstones in the world.

The Colors of Tanzanite

One of the most fascinating things about Tanzanite is the way it shows different colours depending on which direction you look at it from. This effect is called pleochroism, and it's a big part of what gives the stone its distinctive look.

The colour can also shift depending on the type of light it's under. In daylight, Tanzanite tends to lean more blue, while under incandescent light — candlelight included — it often shows more violet or pinkish-violet tones. The finest stones manage to keep an intense blue look no matter the lighting, though in most Tanzanites you'll actually see blue and violet together.

Tanzanite is what's known as an allochromatic gemstone, meaning its color comes from trace elements rather than the mineral itself. How saturated that color is depends largely on the amount and ratio of chromium and vanadium in the stone.

Colours range anywhere from soft pastel tones to deep, rich hues, so there's something for different tastes and budgets. Generally, the bigger the stone, the more the colour intensity stands out — which is why deeply saturated color is harder to find in smaller Tanzanites than in larger ones.

Clarity and Cut

Tanzanite crystals tend to have relatively few inclusions, and a good-quality stone is generally expected to be eye-clean — meaning you shouldn't spot any obvious inclusions with the naked eye when viewing it from a normal distance, about six inches away.

It can be cut into a variety of shapes and styles. Oval and Cushion cuts are the most common, though you'll also find Round cuts and other shapes out there.

No matter the shape, brilliance matters just as much as color. A rich blue is desirable, sure, but how the stone is cut plays just as big a role in its overall beauty. Even a gemstone with gorgeous color can lose some of its sparkle if it's cut too large or poorly proportioned.

A Rare Gemstone of the Modern Era

Tanzanite's rise in the jewellery world has been nothing short of remarkable. Within just a few decades of its discovery, its blue-violet colour had already captured attention worldwide, with demand outpacing most other coloured gemstones — Sapphire being the main exception.

Rarity is a big part of its identity, too. Tanzanite is often said to be around a thousand times rarer than Diamond, and estimates about how much longer its mines will last have only reinforced the sense that it's in limited supply.

Between its unusual color, its one-of-a-kind origin, and a history that's short but eventful, Tanzanite has carved out a place all its own among modern jewellery gemstones.

Tanzanite as a Birthstone

In 2002, Tanzanite was added to the jewellery industry's birthstone list for December, joining Turquoise and Zircon. The addition was particularly notable because the traditional birthstone list had seen very few changes since its standardisation in the early twentieth century.

Tanzanite has since become associated with new life and new beginnings. This symbolism also connects with Maasai traditions, in which blue holds spiritual significance. Blue beads and robes have traditionally been given to women after childbirth, representing blessing, life and a new beginning.

Tanzanite Facts

Origins: Tanzania 

Colors Found: Shades of lilac, blue & purple as well as fancy colours 

Family: Zoisite 

Hardness: 6.50 - 7.00 

Refractive Index: 1.69 - 1.70 

Relative Density: 3.35