What Is Tanzanite - Gemstone Facts and Information

| 14 min read

There are many incredible facts associated with the gemstone Tanzanite. Its peerless deep indigo hue comes to mind, as does its single-location source in the country after which it is named - Tanzania. But we begin this blog with a very rare thing in the history of gemstones - a detailed origin story. Tanzanite was discovered relatively recently, so there are good first-hand eyewitness reports on exactly how and when the gem was found.

We will never know precisely when human eyes first saw Emerald, or Diamond, or Sapphire. But for Tanzanite, we do. Enjoy the story.


Tanzanite Infographic

June 7th 1967 saw the astounding discovery of the remarkable gemstone we now know as Tanzanite. The rarity of this spectacular jewel cannot be understated; it's found only in its home country of Tanzania, and is thought to be at least 1,000 times rarer than Diamond. The conditions required to form Tanzanite are outstandingly unique, rivalling the rarity of the gemstone itself.

On that historic day, a gentleman named Manuel De Souza hired a driver for a short expedition to the north of Tanzania. Eventually, the driver refused to take him any further than the village of Mtakuja. Unphased by this setback, Manuel De Souza pushed forward just four more miles on foot, where he made one of the biggest gemstone finds of the 20th century. As he progressed further from Mtakuja, it was the shine of the gem that caught his eye from the ground. Manuel initially registered the gemstone as Olivine but, after further testing and inspection, the gemstone was discovered to be a gem-quality variety of the mineral known as Zoisite.

Tanzanite Jewellery Selection

The history and culture surrounding Tanzanite is as rich and vivid as the electric combinations of colour that beam from the gem’s surface. Tanzanite owes a large part of it’s renown to its beautiful country of origin, Tanzania, as well as the dedicated people who helped take Manuel De Souza’s discovery from a small scale operation to international success. Among this investigative team of people, Dr John Saul sought to dive deeper into the blue hues of the stone. Saul’s efforts, combined with that of his father’s, Hyman, lead to the discovery that the gemstone was, in fact, a previously undiscovered variety of the mineral Zoisite.

The finding was soon confirmed by numerous institutions, allowing the freedom of branding and mining an entirely new gemstone. Soon after, in 1969, celebrated New York jewellers Tiffany & Co. launched the gem on the public - and it was Tiffany’s who coined the name Tanzanite. Henry B Platt, vice-president and director of Tiffany’s at the time (and also the great great grandson of founder Charles Lewis Tiffany), thought the word ‘Zoisite’ sounded too much like ‘suicide’, and so chose to name the gemstone after its country of origin. Not long after it became available, Tanzanite’s popularity began to soar.

Tanzanite Jewellery

Tanzanite is no doubt extraordinary, even being named as the ‘gemstone of the 20th century’ thanks to that very first discovery by Manuel De Souza, which has continued to be enjoyed around the world long after his passing. The management of the mines since Manuel De Souza’s time has changed hands multiple times, and at times the mines have even been abandoned. Today, however, the Tanzanite mines have been nationalised and divided simply into four blocks named A, B, C and D. These mines are still the only Tanzanite mines in the world, all located around the same spot that Manuel De Souza discovered in 1967: in the shadow of Mount Kilimanjaro in the Merelani area of northern Tanzania.

This makes Tanzanite one of the most precious gemstones discovered to date. Supplies may be stashed in just a small part of the world, but the stone is adored and desired across the globe. We are fortunate and proud to bring you this phenomenal gemstone; it's a gem collector’s dream, and is the perfect centrepiece for any jewellery collection. To take ownership of this jewel is to become part of the legacy of Manuel De Souza, a rich heritage that we hope every Tanzanite wearer is proud to join.


Tanzanite is the birthstone for December and the anniversary gemstone for the 24th wedding anniversary. It has made its way onto these two lists remarkably quickly, considering it was only first unearthed in 1967. The Gemological Institution of America added the gem to the official birthstone list in 2002 - the first time the list had been updated since 1912. Tanzanite is a variety of the mineral Zoisite, which was, at best, a very minor gemstone before the discovery of this vivid blue variety. There is also a red-pink variety known as Thulite, and Zoisite has also been found showing a green hue. This can be seen in the hybrid gem Ruby-Zoisite, which is Green Zoisite that features Ruby crystals growing throughout the stone.

Tanzanite Round Cut Cluster Ring

Gazing into Tanzanite for just a moment is all it takes to fall in love with this spectacular gemstone. In the light of day, deep electric blues evoke that ‘love at first sight’ feeling, and in the evening its subtle flashes of purple, violet and red ignite a deep sense of passion. It is a gemological and geographical phenomenon, so much so that the geological conditions required for the gem to turn into its trademark blue are so rare that it's been described as ‘more astounding than the stone itself’.

Tanzanite is extremely popular due to its trichroic nature, which means that three different colours can be seen when looking at the gem from different angles. In Tanzanite’s case, these colours are blue, pinkish violet and pink, all of which are a wonder to behold.

Tanzanite Marquise Cut Cluster Ring

As with many gemstones, the darker and more vivid its colour, the more valuable it is. Dark blue Tanzanite is currently among the most desired of stones and is, therefore, one of the most expensive gemstones in the world. So enchanted is anyone who sees this gemstone that it is often talked about with the same reverence as Diamonds. We grade Tanzanite using an ‘A Grading’ system; once a Tanzanite has been cut and faceted, as long as it's eye clean (with no inclusions visible to the naked eye), and well-cut with good symmetry, then it qualifies for this system.

We must stress that this is our own internal grading system, and not one that has been officially recognised. This is because, believe it or not, there's not a standardised grading system yet in place for any other gemstone on the market other than the GIA’s grading system for colourless Diamonds. That said, the Birmingham Assay Office, through their grading division Anchorcert, use the same methodology as us - to this day, our grading criteria remain very similar. Once a Tanzanite qualifies, it is then simply graded A, AA, AAA or AAAA depending on the intensity of saturation, and the depth of the tone:

  • A - Light
  • AA - Moderate
  • AAA - Intense
  • AAAA - Vivid

While AAAA (‘quadruple A’) Tanzanite has the deepest saturation and tone and is the most expensive Tanzanite grading, many connoisseurs prefer the slightly brighter and more open AAA (‘triple-A’) stones. It is also important to point out that many other companies have started to use our grading system, but unfortunately it has been widely abused by people naming very pale pieces as AAA or above.

Tanzanite Grading Examples

The story of Tanzanite continues to develop as its popularity advances at a relentless pace. Just recently, the Tanzanian government closed the only large-scale Tanzanite mine in the world. There are a few smaller-scale mines still operating, but their combined output doesn’t come close to that of the primary mine. Why? Quite simply, the Tanzanian government have had enough. Among allegations of unpaid tax and gemstones being taken illegally out of the country, the government decided to surround the Tanzanite mining area with a security wall, and their military began its construction.

Now the wall is complete, there's only one way in and out of the site in the Merelani Hills of Tanzania - a secure checkpoint through which every stone will have to pass.

The government wanted to ensure that the people of Tanzania were the first to benefit from the miracle of nature that lies beneath their soils. They wanted to make sure that the global trading of the gem was fair, safe and legally sound - but this would affect the availability of the gemstone. Today, mining is one of the fastest-growing industries across Tanzania, and the government has been concerned for some time about the returns they see from the wealth of the land.

For decades, Tanzanite has been known as a ‘generational gemstone’, because the remaining underground deposits of the stone have been getting harder and harder to find and extract for at least the last two decades. One way or another, it’s getting more challenging to know how much longer this beautiful blue African treasure will be available for.


Tanzanite Gold Jewellery

Gemstones are as old as time, and in the years since their first discovery they've picked up a lot more than adoring collectors and fascinated mineralogists. Many have gained stories regarding their legend, lore and healing properties, and whilst there's no evidence to suggest that any of these properties are real, it's still interesting to explore the esoteric side of Mother Nature's miracles.

It's worth asking ourselves: 'If you truly believe in something, does that mean it's true'? Scientifically, the answer is no, but what about on a more personal, spiritual level? If you really truly believe that an item in your house is having an effect on you, are you more likely to feel that effect? It's really not for us to say, but it's a very interesting concept that deserves further research.

Once again though, we must point out though that no studies have ever found any therapeutic effects or properties in gemstones, and the following is for your information only.

Being a newcomer to the gemstone scene, Tanzanite doesn’t have a long history stretching back through thousands of years from which to draw associations and legends. However, in its short time so far, crystal healers have associated it with nurturing, emotionally supportive and cheering energies. This has seen it linked with being a good stone to wear to overcome melancholy, and is also often given as a gift to new mums because of its calming and soothing associations. It has also been linked with improving communication, and it’s deep, bright, sumptuous hue has seen it become associated with a sense of self-awakening.


  • Colour Blue with indigo, violet and purple undertones (occasionally green and rarely peach tones)
  • Family Zoisite
  • Mohs Scale Hardness 6.5 - 7
  • Specific Gravity 3.1 - 3.4
  • Refractive Index 1.69 - 1.70
  • Lustre Vitreous
  • Crystal System Orthorhombic
  • Transparency Transparent
  • Chemical Formula Ca2Al3(SiO4)3(OH)
  • Composition Calcium Aluminium Silicate


Tanzanite mine map

Tanzanite is mined in the shadow of Mount Kilimanjaro, in the Merelani (also spelt Mererani) Hills area of northern Tanzania, just south of Arusha National Park. The Tanzanian border with Kenya is around 100 miles north of the mining location, which also lies approximately 80 miles to the east as the border makes its way from the north-west to the south-east of this region. Just beyond the border to the east lies the Tsavo National Park, where Tsavorite Garnet was both discovered and named after. There is one sizeable commercial mine here, along with hundreds of smaller artisanal claims.

The size of the mining area is genuinely tiny - being only around 1.2 miles wide and 4.3 miles long, it's only about twice as long and twice as wide as Central Park in New York! This narrow, rectangular area is split into four ‘blocks’, with blocks A, B and D being reserved for artisanal miners, while the large mine sits in block C.



You’ve heard about the history and the legacy of Tanzanite, but what about Tanzanite jewellery? The most wonderful thing about the gem is that it looks stunning in every setting, every cut and every precious metal. From silver cluster rings to 18K Gold solitaire designs, you’ll be buying into a gemstone that never fails to delight you every time you look at it.

Clicking the below button will take you to every Tanzanite design we currently have in our vaults. There are links at the top of the page to browse by jewellery types, such as earrings or bracelets, and there's also a ‘filter’ button where you can search by price or metal type.

Now is the time to own Tanzanite, and with the sheer variety of designs, tones and price points, your perfect Tanzanite jewellery piece is just waiting to be discovered.


Bi-Colour Tanzanite

As well as the beautiful indigo purple hues that Tanzanite is famous for, there is an even rarer variety that features a mix of the classic shades alongside a light, delicate minty green hue too - and the results are utterly breath-taking. As with pure blue Tanzanite stones, Bi-Colour Tanzanite looks stunning set into any of the precious metals. Yellow Gold adds a touch of elegance and luxury to this variety, while White Gold and Silver let the hues of the gemstone take centre stage and shine.

If you’re looking for something extremely rare and just a little bit different for your jewellery collection, then Bi-Colour Tanzanite would be a fine choice.


Peach Tanzanite

This extremely rare variety of Tanzanite is so challenging to obtain that we’ve only managed to do so a handful of times in our almost two decades of being in the jewellery and gemstone business. You only have to glance at the above image of the gem to immediately see the incredible way the light reacts with this jewel. It’s impossible to know how rare this gem is, but if you manage to obtain a piece, you will be the owner of a real collector’s jewel - it's he perfect centrepiece for your entire collection.

Sadly, at the time of writing, we don’t have a single piece of Peach Tanzanite in stock. If that has changed by the time you are reading this, clicking the below button will take you to the pieces we’ve obtained. Good luck!



If your Tanzanite has lost some of its lustre and brilliance, it is likely in need of a gentle clean. We'd recommend using some warm soapy water (use only a very mild detergent like washing up liquid) and a soft lint-free microfibre cloth. Dampen a part of the cloth in the soapy water and gently brush away at the gemstone until the accumulated dirt is washed away, and your gem should look as good as new.

Don't forget to clean the underside of the gemstone too, as dirt on the back of a stone can stop the light properly bouncing in and out of the stone, giving it a duller than usual appearance. Never steam clean your Tanzanite, and avoid ultrasonic cleaners too.

Jewellery Cleaning Methods


Rough Tanzanite

Tanzanite measures 6.5 on the Mohs scale of mineral hardness. This is softer than gemstones such as Sapphire, Ruby and Emerald, but is still reasonably robust as long as you don't allow any direct strikes to the gem and avoid any sudden changes in temperature. Also, be sure to avoid extreme temperatures.

As with all jewellery, keep each piece in a separate box or pouch if you can, or in a box that stops items rubbing against or scratching others. As always, remove jewellery before exercising, doing housework, or when using any harsh chemicals like bleach or acid.

Jewellery Boxes


Tanzanite is one of Mother Nature’s prettiest creations. At Gemporia, we’re delighted to offer a wide range of designs in a selection of different styles. Whether you’re looking for Tanzanite rings, earrings, pendants, necklaces or bracelets, you are now only a click away from discovering your perfect piece. With continually fluctuating mining yields and the political situation surrounding the stone, there’s never been a better time to add Tanzanite to your collection.

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