Tanzanite Education

Tanzanite Overview

Tanzanites are one of the most popular gemstones emerging in the jewelry industry today. Made from a variety of the mineral zoisite, tanzanites are a relatively recent discovery, having been first mined in 1967. While tanzanite may not have an extensive history as older gemstones, some believe it represents wisdom, dignity, and truth. It also represents the birthstone for the month of December. In the short time that tanzanite has been on the market, it has become a staple in the collections of both jewelers and customers alike due to its vivid colors and incredible value.

Tanzanites are known for their vivid blue and purple colors. These rich colors are the result of trace elements of vanadium present in the mineral. Tanzanite also exhibits pleochroism, a unique optical phenomenon in which it displays different colors when viewed at different angles and in different light. Blue hues are much more prominent in fluorescent light while purple hues are more visible in incandescent light. The colors of tanzanite are quite vivid, making them a popular choice amongst customers, especially those looking for an alternative to gemstones like blue sapphires.

The name tanzanite is derived from its origin - Tanzania. This is the only place in the world where tanzanite can be found. They are an extremely rare gemstone, considered to be over 1000 times more rare than diamonds. However, despite their scarcity, tanzanite still remains a much more affordable option than other precious gemstones such as sapphires and emeralds. This is likely due to the fact that tanzanite is still relatively new to the market and somewhat unknown by general customers. It is this scarcity combined with affordability that makes tanzanite such a popular choice, especially amongst collectors. Many believe that the mines in Tanzania are only a few decades away from depleting, and the price of tanzanite is likely to skyrocket in the upcoming years. For those looking to add to their collection, increase their investment, or simply wishing to own a unique and rare piece, tanzanite is certainly an attractive option.

On the Mohs scale of hardness, tanzanite ranks a 7 out of 10. While it may not be as hard and durable as sapphires or rubies, it is still durable enough to wear for jewelry, including engagement rings. It does require a bit of additional care, but that should not dissuade one from purchasing tanzanite. It is also a great choice for lower-contact jewelry such as necklaces or earrings.

The popularity of tanzanite has only grown since its recent discovery, especially among those in the fine jewelry, art, and fashion worlds. From established jewelers such as Harry Winston, Inc. and Chopard, to trendy artists such as Kat Florence and Rodney Rayner, tanzanite is a very exciting choice. The market for tanzanite jewelry worldwide continues to rapidly expand, allowing jewelers to offer almost a limitless variety of options to their customers.

Tanzanite Quality and Pricing Factors

Unlike most gemstones, there are no individual grading systems for each quality of a tanzanite. Rather, there is a singular letter grade for the tanzanite overall. The basis of this letter grade (A-AAAA) are still the same qualities that nearly all gemstones are judged upon.

Quality of a tanzanite is predicated on three important factors: color, clarity and transparency. Pricing and quality are directly correlated.


Color is the most important quality factor for a tanzanite and is the primary driver of value. General rule is that as color saturation of a tanzanite increases, the value increases. However, as the tanzanite color becomes oversaturated and eventually opaque, the price drops substantially. A very light color tanzanite and an overly dark/opaque tanzanite will generally command a similar price.


Colored gems do not have a standardized grading system and it is extremely rare to find a tanzanite with no eye visible imperfections. This is in stark contrast to Diamonds which have a standardized grading system and utilize magnification to inspect clarity. In the wholesale trade we evaluate tanzanite clarity using the following methodology:

(1) Holding the tanzanite face up 12 inches from the observer's eye

(2) Tilting the stone in various directions to visually inspect if any inclusions are visible

(3) Only imperfections viewable on the crown (top part of the gemstone) are inspected and not the pavilion (back side)

Cut / Transparency

Lapidaries cut tanzanites according to the shade of the tanzanite rough material to get the desired color (the primary price driver). Darker material is cut shallower to allow more light to go through the gem, while lighter material is cut deeper to allow the tanzanite to hold in more light and increase saturation. Cutting tanzanite is an art and requires years of experience.

Transparent gems are the most valuable and allow one to see the true richness of color. The catch-22 with transparent gems is that it is much easier to view imperfections. Finding a tanzanite transparent and eye clean is truly rare. Over-saturation of color leads a gem to be semi-transparent as less light is allowed to escape. Opaque gems tend to be eye clean, but may appear as black.

It is also important to note, larger Tanzanites will have higher saturation of color than smaller gemstones.

Carat / Measurements

The weight of a gemstone is measured in a unit called carats (cts.). There are 5 carats in 1 gram. As discussed above, a tanzanite can be cut deep or shallow to maximize the color of the tanzanite. A deep cut 1 carat tanzanite will appear visually smaller than a 1 carat shallow tanzanite. For this reason, it is best to judge a tanzanite based on millimeter measurements (length and width) and not carat weight.

Click here for our Stone Size Chart which you can print to see the actual sizes of various shapes

Click here for our Stone Size Tool where you can input various measurements to see a basic rendering of centerstone sizes relative to your finger - particularly useful if you are planning to mount the gem in a ring.

Please Note: The carat weight listed on the website for pairs is the combined total weight of the two gemstones.


Unlike other gemstones, tanzanite can only be found in Tanzania. Specifically, a small mining area near the Mererani Hills. There is no such thing as a tanzanite not originated from Tanzania. Thus, the origin of a tanzanite is a non-factor when it comes to determining its quality.


The rich color of the tanzanite is typically the result of heating. This can either occur at a lapidary like other gemstones, or naturally underground. However, labs have no way of determining whether a tanzanite was heated naturally or with a lapidary. Thus, all tanzanites should be classified as heat treated.

Overall Grading Value (AAAAA - A)

Many local jewelers use a letter grading system to educate their customers of quality. To assist our customers to relate to the jewelers grading system, we have provided an overall grade. Please see the full grading scale and description below:

Grading % of All Tanzanite Description
AAAA (Heirloom) Top 1%

Fine quality gems that are typically found at higher end boutiques. They have rich color, slightly included to eye clean clarity and tend to exhibit nice sparkle. These gems tend to appreciate most in value over time due to rarity and high demand.

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AAA (Excellent) Top 10%

High quality gems that are typically found in high end stores such as on 5th Avenue. They have vivid to medium color and slightly included to very slightly included eye clarity.

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AA (Very Good) Top 25%

These gems typically have medium to light color and moderate to slightly included eye clarity. They are usually found at medium to high end jewelers.

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Care Instructions

Tanzanites are generally easy to take care of due to their hardness and durability. To keep your tanzanite jewelry sparkling you may want to clean it to remove the unwanted dirt and residue build up. Here are a few care tips to keeping your tanzanite jewelry clean and shiny.

1) Avoid contact with make-up, harsh chemicals (i.e. chlorine and bleach), moisturizers and abrasives. It is best to take jewelry off when in contact with these items. Never swim or bathe with your jewelry on. It is also best to avoid hard impact activities such as exercising and gardening which may scratch or chip the tanzanite.

2) Clean your tanzanite by pouring lukewarm water in a bowl and mixing with a mild cleaning detergent. Submerge your jewelry until the dirt and residue are moistened. Then use a soft toothbrush to clean the underside of the tanzanite. Once clean, rinse and dry with a soft cloth. For extremely dirty jewelry, you may need to repeat the process.

3) Store your tanzanite jewelry individually and avoid contact with other jewelry to prevent scratching. Keep the tanzanite away from heat and direct sunlight. For every day rings (such as engagement rings), we recommend a weekly rudimentary check to ensure the center gem is not loose. Take off the ring and shake it next to the ear (can also tap) and see if you hear rattling. If you do, immediately stop wearing it and get it tightened.

4) We highly recommend an annual maintenance of your tanzanite jewelry to have the gems tightened and jewelry cleaned professionally. This will ensure your jewelry lasts a lifetime.