Nuttalls Of Chester - Buying Tanzanite Jewellery

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We strongly suggest you purchase your Tanzanite Jewellery carefully, so we have produced this guide to help you in your quest for quality Tanzanite Rings, Tanzanite Earrings, Tanzanite Pendants, Tanzanite Bracelets, and all other Tanzanite loose stones and Jewellery you may be interested in.


What is Tanzanite?

Chemical Properties

Chemical formula: (Ca2Al3(SiO4)(Si2O7)O(OH)).
Crystal Habit: Crystal flattened in a acicular manner, may be fibrously curved.
Cyrstal System: Orthorhombic.
Fracture: Unevan to conchoidal.
Moh's scale: 6.5
Specific Gravity: 3.10 - 3.38
Refractive Index: 1.69 - 1.7

It is a transparent zoisite of a naturally reddish brown colour which can be heated to a stable blue to violet, and was discovered in the shadow of Mt. Kilamanjaro in 1969. Geologists believe that it was the eruption of Mt Kilimanjaro that provided the unique set of conditions for Tanzanite to form. The presence of Vanadium and other important chemicals in the ground combined with the required heat and pressure sustained over 500 million years, led to the creation of one of today's most beautiful gemstones. Although other varieties of opaque zoisite were well known, they made no impact on the gem market. Tanzanite's rise to prominence among retail jewellers and the general public has been rapid and dramatic. Naturally trichroic, the species shows different colours when viewed through each of its three crystal axes: blue, red-violet and yellow-green.

Although the occasional blue-violet stone is found in the rough state (Mother Nature in this case has already provided the heating); the majority of them must be heated to create this colour. Usually stones are cut and polished prior to heating to about 500-700 degrees Fahrenheit, as abrasions, fractures and inclusions in the rough can cause cracking. This means that the cutter has to attempt to orient the stone for best colour prior to the colour change. It is the yellow-green color which is converted to deep blue by this treatment. Another important decision which must be made by the cutter is the choice to go for size (usually the more violet orientation yields the largest stone) or blueness (blue orientation yields smaller gems). A very small fraction of Tanzanite rough heat treats to a green or blue green colour and such stones are valued by collectors.

In the trade, all Tanzanites are assumed to be heat treated and the colour is stable. Initially, blue stones were valued as a substitute for sapphire, but gradually appreciation for the more violetish tones has risen. Tanzanite is used frequently as a ring stone, but with its hardness of 6.5, and it's tendency to cleave, daily wear will dull the finish if not careful, and its brittleness is a hazard unless protected by a suitable setting. This lovely and expensive stone is also suited to earrings, pendants and all other types of jewellery.

View all our Wonderful Tanzanite Rings

When purchasing Tanzanite there are several factors you need to consider - these are the 4 c's - Colour, Clarity, Carat Weight and Cut.

Tanzanite Colour

The deep blue of the Tanzanite is fantastic, and runs from ultramarine blue to light violet-blue. The most coveted colour is a blue surrounded by a delicate hint of purple, which has a particularly wonderful effect in sizes of over 10 carats. The well developed polychromaticity of the tanzanite is typical: depending on the angle from which you look at it, the stone may appear blue, purple or brownish-yellow. Having said that, most raw crystals are somewhat spoiled by a brownish-yellow component, though it can be made to disappear by the cutter if he heats the stone carefully in an oven to approximately 500 - 700°. During the procedure he must pay careful attention to the moment at which the colour turns to blue. This burning is a method of treatment which is regarded as customary in the trade, but the raw stones must be as free of inclusions as possible, since otherwise fissures may occur. In fact working with Tanzanite can sometimes give even the most experienced cutter a bit of a headache, the cleavage of this gemstone being very pronounced in one direction. This exclusive gemstone is cut in every imaginable shape from the classical round shape to a number of imaginative designer cuts.

A Tanzanite will continue to fascinate with its unusual, captivating aura. Its deep blue with the slightly purple tinge is one of the most extravagant colours known to Man. It personifies immaculate, yet unconventional elegance. A person who acquires one of these exclusive gems is someone who wishes to set himself apart from the hoi polloi. A person who wears it exudes confidence and individuality. The almost magical colour of a perfectly cut Tanzanite is one that not only suits confident young women; it is also excellently suited to underlining the individuality of the more mature woman.

There is only one universally accepted official grading system for coloured gems and that is the GIA system (Gemological Institute of America). However, there are numerous trade based systems as you will see when surfing the web. The majority of these are very subjective and vary widely. One of the terms commonly used (and misused) in the trade is AAAA Tanzanite. This is a term used by the miners to denote the very top grade of Tanzanite - the very deeply saturated exceptional stones.

Below Tanzanite loosely representing the colour grades as they descend. We have used the GIA system but included some of the other trade grades often used to help with comparison purposes. Of course there are many other colours which fit in between these but it serves as good basic guide to colour.  
GIA GRADE               GIA GRADE                                                 GIA GRADE
bV 6/5 or vB 6/5          bV 6/4 or vB 6/4 or bV 5/5 or bV 5/5             bV 4/4 or vB 4/4 or bV 5/3 or vB 5/3
OTHERS                    OTHERS                                                      OTHERS
AAAA                        AA, A, vB1, Bv1, Fine                                  B, vB2, bV2, Fancy 1
vB 1+
bV 1+
Investment Grade
Vivid Exceptional

Tanzanite Jewellery shows true "pleochroism"- the viewing of different colours from different directions within the stone. When you look at Tanzanite Jewellery in daylight, they exude vibrant royal blues, but under candlelight show off luxuriant deep purple hues.

View all our Amazing Tanzanite Earrings

Tanzanite Clarity

The clarity of Tanzanite, as with all other gemstones, is officially classified as ranging from the best VVS (very, very, slightly included), to VS (very, slightly incuded), SI-S2 (slightly incuded), and down to I1,I2,13 (included).

Clarity is the second most important of the 4 c's when considering Tanzanite quality. Clarity simply refers to how inclusion-free a gemstone is. Once again, the most universally accepted and most documented system is the GIA system but there are also numerous other trade based systems in use. The basic rule with Tanzanite is that it should be at least eye clean but preferably loupe clean too. Top stones are loupe clean.

Tanzanite Weight (carat)

The gemstone is readily available in most sizes. Most commonly found in the 0.1 - 0.5ct size, they start to become scarcer up to 1.5cts and over 3.0cts even scarcer. Up to around 10 - 15cts they are still relatively available. Tanzanites exist even in the 100+ carat range but these are extremely rare.

Tanzanite Cut

Although it has the least impact on value of the 4 C's cut is still important. In the market, Tanzanites are found in a variety of shapes and cutting styles. Ovals and cushions are the most common, but rounds are also seen, as are other shapes, including emerald cuts, trillions, etc. Cabochon-cut Tanzanites are not often seen. Cuts should be proportional - you don't want to pay for a stone with a lot of weight in the pavilion for example when this weight will be invisible in a setting.

Tanzanite Prices

Almost any price you care to name is being asked - and paid! - for Tanzanites of good quality and large size. What makes this stone so popular? Is it simply that fantastic colour? No, it is also the exclusivity of its origin. The stone is particularly highly prized because it is found in only one place in the whole world. The idea of possessing something that not everyone has has always been one of the main criteria in the way we esteem special gems.

Recent disastrous weather conditions, government embargos and continuing political tensions have restricted the supply, especially of larger fine colored stones.

View all our Superb Tanzanite Pendants

Other Information

Fakes, Synthetics and Immitations.

Tanzanite has never been synthesized, but a number of imitations exist. The most common is blue-violet glass. A synthetic fosterite has also been used as an imitation and is known as Tanzanique in the trade. It has a lower RI than Tanzanite and does not have the same pleochroism so is easily distinguished from the real thing. However, laymen can easily be fooled so always buy from a reputable dealer, preferably a member of the ICA (International Coloured Gemstone Association) which has a strict code of ethics.

"AAA" or "AAAA" Quality.

Whilst many sites proclaim to be selling AAA stones from Block D, most are actually dealing in the A range. Prices are considerably lower for this material and it has become a marketing ploy to represent lower cost material as AAA (bV 6/5 vB 6/5) at low prices. True block D AAA material is very rare and difficult to get. Less than 1% of all Tanzanite production is true AAA and it is considered exceptional. It is thus at a premium price right from the mouth of the mine to the very few highly selective and high end jewelers who have access to it. Beware of sites offering this exceptional material at prices too good to be true. Chances are you will be buyng a grade to several grades lower. This is fine as even lower grade Tanzanite is very beautiful, but it shouldn't be misrepresented as AAA or AAAA.

"Block D Tanzanite"

Block D Tanzanite is a term commonly used in marketing Tanzanite. Block D simply refers to the area from which material is mined. The Tanzanite mining area has been divided into 4 blocks by the Tanzanian government - Blocks A to D. Traditionally, larger quantities of the best material was found in block D so the term became synonymous with the top grade. However, it has become a bit of a marketing ploy recently and is a term misused as it implies that only block D produces the AAA grade. This is not the case - AAA comes from all blocks, block D has traditionally just produced more of it than the others. It is best to ignore the term as it is simply a marketing ploy and it is largely misused. It is better to use more scientific and official grades like the GIA system than to rely on subjective trade terms.


Virtually all Tanzanite of a blue/violet colour has been heat-treated to enhance the colour. In the rough state most Tanzanite is predominantly brown. Heating at 500 to 700 degrees centigrade causes this colour to change to blue. This is a permanent and stable change, and is universally accepted throughout the jewellery industry.


A great deal of Tanzanite marketing makes a big deal of the "red flash" phenomenon of Tanzanite. This is one of the features of the stone and is due to Tanzanite's trichroism. Tanzanite is extremely light sensitive, with incandescent lighting (yellow lighting found in common light bulbs) tending to shift its colour to the violet side causing the red and pink flashes to appear within the stone.

Tanzanite as an Investment

A theory touted by many purveyor of Tanzanite - "Tanzanite is the gemstone investment opportunity of our generation". Is this really the case or is it simply more marketing hype?

Tanzanites' Unique Niche

Tanzanite occupies a unique niche. It is one of the world's rarest gemstones, found in only one place in the whole world. The likelihood of Tanzanite ocurring and subsequently being discovered in a different location are highly unlikely. This effectively sets the stage for the economic reasoning why Tanzanite may be considered a viable and potentially excellent investment.


The principal factors in a free market economy, are demand and supply. In the case of Tanzanite, both are overwhelmingly in its favour. Demand is growing exponentially for this gemstone. In the US market, the largest market for Tanzanite, the growth is both organic and ochestrated. Organic, driven by consumer's appreciation of this beautiful gemstone and jeweler's subsequent advocation of its qualities, and orchestrated; largely due to voracious marketing on the part of Tiffany & Co. in the early years and more recently by Tanzanite One. Tanzanite One is a Tanzanite marketing firm listed on the London Stock Exchange, seeking to make Tanzanite the stone to buy at the birth of your first child. If successful, this campaign is expected to have a similar effect on Tanzanite as De Beers' "Diamonds are forever" campaign did on Diamond sales in the mid nineteen hundreds. Their campaign had the effect of making Diamonds synonymous with engagements and diamond rings as symbols of engagement, subsequently driving diamond sales stratospheric. If the campaign to make Tanzanites and Tanzanite jewellery synonymous with the birth of one's first child is similarly successful the expectation is that the demand side of the equation will be effectively taken care of worldwide.

This factor is also bolstered by Tanzanite's fairly recent inclusion in the Birthstone list. Tanzanite was named as a birthstone for December - the first time the list has been altered since 1912. An auspicious and important factor in assessing Tanzanite's popularity and hence the demand for this gemstone.

View all our Enchanting Tanzanite Engagement Rings

Future Markets

Aside from the world's established gem markets, there are several new and upcoming markets which are further increasing the potential demand for Tanzanite, notably India and China. As these markets develop, gemstones sales in general will benefit enormously, as both cultures have long standing love affairs with precious stones. More notable is the fact that both cultures have a love for colored stones with metaphysical properties. Tanzanite, as a rare and revered gem with connotations that its pure violet blue depths have healing properties (metaphysically, Tanzanite is said to activate and integrate the energies of the heart, throat, third-eye, and crown chakras, creating a condition in which the mind and psychic abilities are activated and guided by the wisdom of the heart) makes it the natural choice of an annually growing market of Chinese and Indian buyers. As their appetite for Tanzanite grows, the increase in demand could be extraordinary.


The preceding paragraphs have explored and effectively demonstrated how the demand side of the economic curve is amply catered for in Tanzanite's case. Just as important, is the supply side however, as an increasing demand for an item can be amplified immeasurably in economic terms if it is matched by a corresponding decrease in supply. This is exactly what is, and has been happening with Tanzanite for some time. Supply is becoming increasingly limited as the world's only source is mined frantically to keep up with enormous and growing demand. The result is that the stone is becoming increasingly difficult to find, especially in the finer qualities which traditionally constitute less than 1% of total production. Certainly, in the many years we have been dealing in Tanzanite, we have noticed an unprecedented decline in the availability of fine AAA stones despite our proximity to the mines. There simply is very little of this precious material being found today. Latest geological estimates have indicated that the life of the mines may only be 10 more years at present production rate but if present market conditions prevail, we believe that the very finest Tanzanite will become unavailable long before that.

In Summary

It is clear that with rapidly growing demand and supply shrinking, simple economic theory dictates that Tanzanite prices will increase substantially. Already there has been a threefold increase in just 6 years. However, further to our expectation of gradual increases over time, many gemologists and speculative investors are of the opinion that the stone's real value as an investment lies in the potential for astronomic prices once it has been mined out, and the world's enormous demand for Tanzanite can only be catered for from what exists in private hands. At that point, Tanzanite values, most especially for the finest material, will be extremely high. There are other gemstones with a similar history from which we can draw parallels. Paraiba Tourmaline, for example, found in the late 1980's in Brazil, mined out by mid 1990's can now cost as much as US$20,000 per carat. Alexandrite, found in the Ural mountains of Russia a generation ago and extremely rare in fine qualities is a similar price. Both stones traded close to Tanzanite prices do now in the days when they were being mined.

Many factors combine to indicate that Tanzanite is uniquely placed in the gem kingdom to be a potentially excellent investment. Its final and heretofor unmentioned advantage over other investments such as stocks and bonds is that it is a tangible asset - a thing of beauty that can be flaunted and enjoyed as its value increases.

View all Our Amazing Tanzanite Jewellery

Our Last Word......,

Expect to pay more for larger size gems and remember; at the end of the day, "beauty is in the eye of the beholder'". So choose the stones you want, not what you are led to believe you want! Whichever colour, size or shape of Tanzanite you choose, be sure to wear it and ENJOY IT!

With our exciting range of Tanzanite Jewellery, you can be sure that buying your Quality Tanzanite Jewellery from us is simple, hassle free and an enjoyable shopping experience. In our collection you can find a vast range of Tanzanite Pendants, Tanzanite Rings, Tanzanite Earrings, Tanzanite Bracelets, and much, much more! 

Thank you for reading this article - We sincerely hope it helps in some way.

Visit us at: – Fine Quality Jewellers.

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