Tanzanite Gemstone Information

Introduction

Imagine being the person who discovered a gemstone rarer than diamonds. What a story that would make and that is the story of Maasai tribesman, Ali Juuyawatu, who discovered tanzanite in the hills of northern Tanzania near the majestic Mount Kilimanjaro.

As with all stories about finding treasure, there is a bit of mystery about the discovery of tanzanite. The most commonly believed story is that Maasai herdsmen were tending their cattle in the hills of Tanzania not long after a fire had burnt the grasslands in 1967. Brown stones and rocks littered the landscape as per normal but this day the herdsmen notice a blue glow to some of the rocks. They took the rocks to a local amateur gemologist, Manuel de Sousa, who thought he had a trove of sapphires in his hands. After identification procedures were done, it was discovered that the stones were in fact rare zoisite crystals.

When Henry Platt, the President of Tiffany's, first saw the gemstones (tanzanite) he declared it to be "the most beautiful gemstone to be discovered in 2000 years".

However he had a problem with the name, Blue Zoisite, he felt would have no appeal to the ladies! So he re-christened it Tanzanite after the country in which it had been discovered and ordered his company to promote this gorgeous new gemstone.

Meanwhile Manuel de Sousa had staked mining claims in the area where the Maasai had discovered the stones and anticipated his new found wealth and fame. Unfortunately he could not control the mines and estimated that 80% of all the gemstones were stolen before he could sell them. He died shortly after in 1969 in mysterious circumstances in a car crash. Since then the mines have seen natural disasters, looting by gangs, nationalization before a recent period of settlement has led to a consistent supply of the gems.

Things get a little murky however when we discover that in the U.S. Gemological Survey records, it lists an identification of a blue zoisite crystal by Dr. William Pecora in 1959. Then we have Jumanne Ngoma, who was awarded a certificate and a prize of $22 by the government of Tanzania in 1984 officially recognizing him as the discoverer of Tanzanite. And Ngomo says the country's president Julius Nyerere came up with the name, Tanzanite!

All these questions, riddles and twists in a gemstone that was discovered in the last 50 years or so.

Tanzanite is known as a blue gemstone but it is so much more than that. Its colors vary from light almost sky blue all the way up to a deep midnight blue. Add to this blue some flashes of red and touches of violet and purple and you can see why this gemstone really catches the eye.

When grading diamonds, the whiter the stone the higher the value, however with colored gemstones the more vivid and saturated the color the higher the value.

Tanzanite has possibly the most beautiful blue tint in the gem world - even sapphires can look a bit washed out next to a tanzanite.

A chart has been created to act as a guide when valuing tanzanite although personal preference should always be taken into account.

Firstly there is the dominant color, either violet or blue, with blue being more expensive. Then there is color saturation, the deeper the color the better and finally tone with darker stones being more desired. Be a little bit careful here as a dark stone without strong coloring will not be so highly rated.

There are many color charts out there rating colored gemstones and the different styles and opinions can get confusing. Diamonds have a standard chart which follows strict regulations but these other charts can give away AAAs, AA+s, B-AAs with abandon so look out as these are only guides.

On top of this outstanding color range, tanzanite also has a unique ability to change color depending on the angle it is viewed and not just from one color to another but three different colors. In one exquisitely cut stone you could see blue, red and purple blaze before you as the gems turns from one side to another. This phenomenon is called pleochroism and it is quite rare, especially in a three color range.

Tanzanite is the blue form of zoisite, an aluminum silicate mineral which is formed by high heat in rocks.

Tanzanite is the most famous of the zoisite crystals but other forms include Anyolite which are a mixture of ruby and green coloring and Thulite, the pink variety.

When pricing colored gemstones we need to consider what is known as the 4 Cs, color, clarity, cut and carat and usually it is the color that is the most important.

With Tanzanite the color we are looking for in an ideal and valuable stone is a deep saturated blue, with violet and red flashes in the top gems. For a few reasons the blue is valued a little higher than stones with a more purple hue. A good even color with no color variations or zones is also highly valued.

Cutting Tanzanite has its own particular issues. Once cut the stones will visibly change color when viewed from different angles, in the case of tanzanite there can be three colors on show! The cutter will try to show off the pure blue color as much as possible although this can mean a lot of the stone is sacrificed. So in the case of Tanzanite the cut is doubly important when pricing.

If you have done any sort of research into colored gemstones and their value, you will have come across the old adage, 'color is king', and tanzanite is no different. But which color is the ruler in the kingdom of tanzanite? Blue. There, that was easy, wasn't it! Tanzanite is available in blue, purple or violet-blue but the bluer the better.

Other factors come into it with the ability of tanzanite to change color when viewed from different angles so the blue may flash to red or purple and it moves around. Larger gemstones also seem to have more depth to the color, more vividness.

Tanzanite can also look a little different under various light sources, fluorescent lights show a bluer stone while incandescent show up the red colors more, candlelight can bring out burgundies and sunlight fires up the blues.

Tanzanite that makes it to the cutter's table is usually free of blemishes or inclusions that are visible to the naked eye. Any gemstones with obvious flaws or even fractures would be devalued considerably.

The strong even blue colors that are so highly prized in a tanzanite gemstone are usually only found in a larger carat weight stone. This depth of stone needs to be around 5 carats or more to really appreciate the deep blues while smaller stones tend to have a lighter more subtle coloring.

Colored gemstones have a wide variety of relative densities, for example a 1 carat sapphire is considerably smaller than a 1 carat - while a 1 carat emerald would be quite a bit larger. Because of this, we suggest buying gemstones such as tanzanite by physical size, the width in millimeters, rather that carat size, so you know exactly what you are getting.

Tanzanite gemstones have only been mined for a few decades and are only sourced from one small strip of land barely 4km in length. They are exquisitely beautiful, nearly mined out and are 1000 times rarer than diamonds. Despite all this, diamonds are still considerably more expensive in like for like cut gemstones than tanzanite.

Why, you might ask.

There are several reasons, not least the excellent marketing and control of the diamond industry. There is no industrial use for tanzanite unlike diamonds although this is not really a good reason for such a price disparity. The government of Tanzania ran the mining industry for 30 years soon after the discovery of the gemstones in the late 1960s but had no experience or expertise so did not do a very good job.

Illegal mining, smuggling, poor marketing, poor policing and poor policies have all contributed to a perhaps undervalued gemstone but things seem to be turning around. A combination of better governance, a high demand in Asia for colored stones, a likely exhaustion of the mines and no likelihood of an alternative source should see prices rise though probably not to the levels of diamonds.

Of course diamonds are harder, shinier and more famous than tanzanite so that helps boost their price!

As with diamonds, Tanzanite despite being the rarer of the two and arguably the more beautiful and striking is valued less than the sapphire. Let's take a look into why.

Sapphire's history. Sapphires have been admired and desired for centuries if not millennia by the rich, the powerful and the royal. Tanzanite is a new gemstone without the long and distinguished past of its blue rival.

Hardness or durability. Sapphire wins out here with its hardness on Mohs scale up at 9 just behind that of diamond at 10. Tanzanite ranks at only 6 to 6.5 so it can be scratched quite easily and even broken if struck too hard. Care in mounting with protective bezels is a good idea for tanzanite gemstones.

Prestige. Sapphires have a status equaled but not bettered in the gems world, only diamonds, rubies and emeralds can compare. Possibly the most famous piece of jewelry, Princess Diana's engagement ring, was a sapphire so it is difficult for gems even as beautiful as tanzanite to compete.

What the future holds is hard to predict, as tanzanite becomes rarer and rarer, becomes more well known and gains new fans of its stunning color changes perhaps it will begin to challenge the prices reached by sapphires.

We at GemSelect do not offer investment advice and I would strongly suggest getting as much independent guidance as possible whenever contemplating any kind of financial speculation. That being said Tanzanite is a fairly unique gemstone which makes it an appealing prospect for investment. Tanzanite is only found in one location in the world and has only been mined in this location for a few decades.

This area is almost certain to be depleted of minerals in the not too distant future meaning no new gemstone being introduced to the market. Quite soon all tanzanite will be resold gemstones, there will be no first time owners.

A similar situation arose with Paraiba Tourmalines quite recently. It was discovered in the 1980s within a decade the mine was exhausted, nowadays high quality gemstones reach 10,000 or even 20,000 dollars a carat.

Of course, whenever buying gemstones, first look for a reputable dealer, then remember the 4 Cs, color, clarity, cut and carat, then think very carefully again before deciding to invest any hard earned money into these wonderful rare gems.

High quality Tanzanite gemstones are usually a deeply saturated deep blue or a deep bluish purple color, but which is more valuable? Obviously a person's preference comes in here and what one person will love another will not but as a general rule it is the blue that has the higher value - assuming cut, clarity and carat are the same or similar.

Why? It is probably as simple as the blues are just that little bit more rare and a little bit more difficult to cut for maximum 'blueness'. Before beginning on a gemstone, cutters must examine the tanzanite rough and decide if they can cut it in such a way as to maximize the face up blue color. This primary blue is more difficult to achieve than the purple and results in a smaller stone.

Both colors are beautiful and valuable but blue just reaches a slightly higher price.

Tanzanite was only discovered in the 1960 so it does not have a long spiritual history but its formation and discovery reveal an intangible link to the metaphysical. Tanzanite was born half a billion years ago as the sacred Mount Kilimanjaro bubbled away nearby. It lay crystallizing in the earth's crust for hundreds of millions of years working its way towards the surface. A bolt of lightning set the hillsides around Africa's most famous mountains and set the countryside ablaze. When the fires had subsided, Maasai herdsmen, tending their cows, noticed a strange blue glow within the usually dull brown stones and rocks that lay on the charred ground. They had discovered Tanzanite.

The Maasai believe the gemstone is a gift from the gods as the color blue has always been sacred to them. This gift from the fires has led to a tradition where a gift of tanzanite is given to a woman after the birth of a child to bring good fortune.

Tanzanite is a linking stone, able to bridge the gap between the physical world and the spiritual world. It will allow your psychic abilities to flourish and aid clairvoyance, intuition and self knowledge.

Tanzanite's range of colors from blue to purple mean it has influence over three chakras, the Throat, the Third Eye and the Crown. These Chakras once again emphasize the connection between the physical and metaphysical planes as well as clairvoyance, creativity, communication, peace and calmness. A very powerful gemstone.

Tanzanite is found in one small location in Tanzania not too far from Mount Kilimanjaro in the Merelani Hills in the Lelatema Mountain range on a small strip of land which is barely 4km long.

The Great Rift Valley extends nearly 5000 kilometers from Syria in Middle East Asia all the way down the Mozambique in Southern Africa. This rift is slowly but surely splitting Africa into two and is the meeting point of two tectonic plates which have been grinding together for millions of years.

The volcanic activity here has produced Africa's highest peak, Mount Kilimanjaro and its second largest lake, Tanganyika. Volcanic activity and the subsequent cooling magma and lava has helped form many of the world's precious gemstones and emeralds, rubies, sapphires, garnets, tourmalines and topaz are just some of those found here.

Sometime in the earth's geological past in the area around Mount Kilimanjaro two shelves of igneous rocks containing mineral rich magma were forced together by movement of continental plates mixing and combining the materials which eventually produced tanzanite gemstones.

Gemstone crystals are formed by water and minerals squeezing their way into cracks in volcanic rocks. This occurs in many areas around the world where there is a history of volcanic activity. What is unusual in the case of tanzanite is to have some minerals from one plate mixing with minerals from another plate to produce such a unique gem. This is why it is only found in this particular site and is unlikely to be found elsewhere.

When tanzanite comes out of the ground it tends to a brown color with hints of yellow, red and purple, the locals in Tanzania call it diesel colored because it looks like the color of the fuel they use for their trucks! Interesting, but unlikely to set hearts aflutter when made into jewelry.

To turn this rough crystal into the brilliant blue purple gem so admired around the world it needs some heat treatment. Quite gentle treatment compared to some gemstones, maybe half an hour at 600°C is all it needs to produce a world class beauty ready for the cutter's table.

Heat treatments and irradiation are both causes of controversy in the world of gems with some people very much against it and others seeing no problem. The simple fact is that some gemstones are undoubtedly enhanced by treatment and so long as that treatment is honestly and clearly disclosed to the customer then it is okay.

Tanzanite is rated at 6.5 to 7 on hardness scale so it is lower on the list, quartz is harder, so are zircons and sapphires. However this is all quite relative so we would say that tanzanite is certainly strong enough to be made into almost any type of jewelry so long as we take a few precautions. Rings should be made in protective settings and should not be worn when partaking in strenuous activities. Earrings and necklaces or pendants should be no problem at all.
To learn more about the Mohs hardness scale please read our article here

Tanzanites are becoming more and more popular as an engagement ring and with the proper setting this should be okay but we would suggest tanzanite as a more event or special occasion piece of jewelry. Gems with rounded or low edges can be worn more often but cornered shapes like emerald cuts are more likely to be chipped.

You will want to prevent scratches to your tanzanite from harder gems (sapphire, diamonds, etc.) when stored. Therefore, it is a good idea to keep your tanzanite separate from all other gems of different hardness in a fabric-lined compartment of a jewelry box. Individual cloth jewelry bags are also suitable if you have limited space in your box.

When tanzanite became available in the late sixties we had a new blue gemstone of high quality and high value so it was added to the other high value blue stones and is now an official birthstone for December.

Birth months and zodiac signs have been linked with gemstones for centuries, possibly going all the way back to the breast plate of Aaron, the brother of Moses, mentioned in the bible. These gems have changed over the years, been renamed, been mistaken for other gems and varied from culture to culture.

About 100 years ago the gem industry in the United States decided to set out the 'official' birthstones for each month (very much a money spinner more than a cultural event). December was originally designated turquoise and lapis lazuli so was definitely a blue tinged month.

Now we have tanzanite, turquoise and zircon to choose from for gifts to loved ones born in December or perhaps if you are a December baby to wear for yourself.

It is also the suggested gift for those celebrating the 24th wedding anniversary.

• Welcome to D Block

  The mining area of Merilani, where all tanzanite gemstone originate is divided into 4 sections, A, B, C and D. "D block" is the sector that has the reputation of producing some of the finest and largest quantity of tanzanite over the years.

• Beware though, since this reputation has emerged, some dealers will happily say D block even if they have no idea of the gemstones origins.
• What's in a name?

  It is rumored that the advertising department at Tiffany's misheard the term blue zoisite as blue suicide so quickly changed its name.

• Style icons such as Cate Blanchett, Penelope Cruz, Beyoncé, and Sarah Jessica Parker have all been spotted rocking tanzanite jewelry.
• "The Mawenzi"

  The biggest tanzanite in the world is a single large crystal of 16,839 carats, well over 3kg. It has been named after Kilimanjaro's second highest peak.

• After the Duchess of Cambridge was seen wearing tanzanite jewelry it soon became the #2 most popular gem in the UK and #1 most popular in Wales.
• The Eyes have it

  The color of tanzanite is similar to two of the most popular gems, sapphire and amethyst. The mix of these two colors is often said to look like the beautiful violet eyes of Elizabeth Taylor.

Tanzanite is associated with good luck and prosperity, it is given to new mothers or babies amongst the Maasai people, on whose land tanzanite was discovered, to bring good fortune. Blue has always been a lucky color in the area around where tanzanite is now mined and indeed in many parts and cultures of the world. Discovering such an outstanding blue gemstone in your backyard has only intensified this feeling of good luck that is linked with tanzanite.

Tanzanite gemstones and jewelry should not be subjected to extreme heat or sudden temperature changes. Additionally, tanzanite should not be exposed to acid. Avoid the use of ultrasonic and steam cleaners. The best way to clean tanzanite gemstones is by using soapy water and a soft cloth. Be sure to rinse well to remove soapy residue.

Always remove any jewelry or gemstones before exercising, cleaning or engaging in vigorous physical activities such as sport. Store tanzanite gemstones away from other gemstones to avoid scratches. It is best to wrap gemstones in soft cloth or place them inside a fabric-lined jewelry box.

Obviously a certified gemstone from a reputable dealer is the best approach but this is not always possible when you are out searching for a great gemstone or a bargain!

Here are a few simple tips that may help. A real tanzanite can change color depending on the angle you are looking at it from, look at the top and see blue, turn the gem slightly and it should change to purple. Tanzanite is one of the few gemstones that can show three colors from three angles but this may not be clear but flashes of red or pink in addition to the blue and purple and it will almost certainly be tanzanite.

Check the depth of the color from all sides, some stones can be coated on the bottom and look blue from the top. Look into the side of the stone to see if the blue is just as intense. If not you may have a fake in your hands.

To the naked eye most tanzanite will look completely clear with no internal blemishes but with a jeweler's loupe or magnifying glass you should see some flaws. Imitation stones or stones created in a laboratory will be flawless.

Check the price. Tanzanite is a rare and beautiful gemstone and the price should reflect this. There are bargains out there and discounts to be got but if the price seems too good to be true it probably is.

A simple hardness check may expose a fake. Tanzanite has a hardness of 6.5 to 7 on the Mohs scale, so it is harder than your fingernail or a penknife, if either of these can scratch the gem in question, it is not a real Tanzanite.

This is not a complete guide on how to spot a fake tanzanite gemstone but I hope it helps.

At GemSelect, we currently offer brief identification reports from your choice of two well-respected independent gemological laboratories, The Asian Institute of Gemological Sciences (AIGS) and Burapha Gemological Laboratory (BGL Lab).

There are a couple of things which make tanzanite so unique. Firstly it is found in only one place, a small mining area in the foothills of Mount Kilimanjaro in Tanzania. Opinions differ on how long the deposits of tanzanite found here will last, 10 years, 20 years, it is only a matter of decades before they run out. At this point, tanzanite will only be considered an even rarer gemstone.

Secondly it is a gem that can change color when viewed from different angles, a phenomenon called trichroism (which means three colors). This is rare amongst gems and in the case of tanzanite it usually means a combination of blue, purple and red depending on the angle.

Some gemstones show a distinct or dramatic change in color under different light sources. Look at a color-change garnet under electric or artificial light and it could look red, take it outside into the sunlight and all of a sudden it is green! This remarkable effect only occurs in a few gemstones, Alexandrite, color-change Garnet, color-change Sapphires being the most well known.

Tanzanite is not considered a color change gemstone other than in the most superficial way when exposed to different lighting conditions.

There are some anecdotal reports of sub standard heat treated stones or even naturally heated gemstones which change color dramatically when moved from natural sunlight into electric light however Tanzanite is not thought of as a color-change gemstone.

We have spoken about the importance of color when choosing a tanzanite gemstone, indeed all colored gems, but what else should be considered?

Tanzanite's weak spot is its relative low ranking on the hardness scale, only 6.5 to 7, meaning it could be scratched or broken. When selecting a gem look out for chips, cracks, scratches that can devalue a gemstone. If it is a piece of jewelry, make sure it is in a protective setting and not exposed too much. Earrings or pendants are also better than rings as they are less likely to knocked about by day to day activities.

Tanzanite is thought of as a type 1 gemstone so should be visibly flawless, no blemishes or inclusions that can be seen within the stone by the naked eye. Any such flaws will decrease the stones value significantly.

The cut of the tanzanite gemstone impacts the price dramatically. The ideal cut will maximize the brilliance or sparkle as well as the color changes from blue to red to purple.

Look out for some techniques used in the cutting industry which will maximize the carat weight of the stone to the detriment of the cut. The stone may be a bit 'fat' at the back (pavilion) which increases the weight but will spoil the sparkle. The shape of the stone is more of a personal preference and tanzanite can be cut into almost any style.

Then there is the carat weight of tanzanite. Color and clarity really make the price of tanzanite but of course a bigger stone of equal color saturation and flawless clarity will always be more expensive than its smaller cousin. However do not be tempted to buy a lesser quality gem just because it is 'big'.