Tanzanite is most famous for its rich violet-blue color, but there are now a range of other colors being marketed as fancy color tanzanite. Some of these are quite rare and valuable and thus popular with collectors.
The violet blue tanzanite is produced by low temperature heating of the brownish or greenish zoisite found in Tanzania. The name tanzanite was orignally applied to this distinctive color when Tiffany & Co. named and marketed the gem after its discovery in 1967.
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| PInk Tanzanite Crystal |
There was initially no market for the unheated zoisite, most of which was not particularly attractive until heated. But with extensive mining in Tanzania, some rare and beautiful colors of natural zoisite have been found and these are now sold as fancy colored tanzanite (though technically they should be called "fancy colored zoisite"). The colors include green, golden, orange, green-blue, pink and purple.
The key to value in fancy color tanzanite is the purity of the color. Most zoisite has a brown or grey secondary hue, and these muted colors are not desirable. Vivid pinks, purples, greens, yellows and oranges are rare and are sought after by collectors. Most fine fancy colors are found only in small sizes (under 1 carat) and larger pieces are very rare, especially in the purer colors.
The opaque massive form of pink zoisite is known as thulite and is relatively common. But the pink color is very rare in crystalline form, and transparent zoisite in any shade of pink is quite valuable. The pinks and purples are the rarest and most valuable of the fancy tanzites, often selling for 2 to 3 times the price of fine blue tanzanite. The chrome green tanzanite is the next rarest, followed by vivid oranges and yellows.
In the case of violet-blue tanzanite, there is no premium for unheated stones, since the violet-blue color is normally produced by low temperature heating. The fancy colored tanzanites are completely untreated, a fact appreciated by many collectors.
See our collection of Fine Tanzanite
Notable Gems from the AJS Collection
This month we feature acquisitions to our collection.
Click on a photo to see the details for the item.
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2.02 ct Unheated Ruby from Madagascar
A very fine unheated natural Ruby from Madgascar. This is beautifully clean material with a pure deep red color. Certified by GemResearch Swisslab (GRS) as unheated, with color graded as "vivid red (GRS type 'pigeon's blood')". This is a fine collector's gem that your family will treasure for generations. |
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A gorgeous saturated royal blue sapphire over 2 carats! This rare unheated sapphire comes complete with a certificate from GemResearch Swisslab (GRS), noting no thermal enhancement and color graded as "vivid blue (GRS type 'royal blue')". This fine gem has wonderful color and beautiful material. It is extremely clean and superbly cut with excellent proportions and polished to a high brilliance. A fine collection-quality gem for a special piece of jewelry. |
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19.87 ct Citrine from Uruguay [SOLD]
A big, bright citrine in a vivid golden orange! The portuguese cut gives this large stone a lot of fire. An impressive gem at a very modest price. Guaranteed natural and untreated. |
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9.56 ct Petalite Matched Pair from Brazil [SOLD]
Petalite is one of the most popular of the colorless gems. It has reasonably good hardness (6 to 6.5) and tends to display a pure white without heat treatment. This matched pair of petalite pears and completely clean and will set up beautifully in earrings. Guaranteed natural and untreated.
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4.65 ct Fancy Tanzanite from Tanzania [SOLD]
A rare purple tanzanite, completely natural and untreated. This fine gem has a wonderfully pure saturated color and is completely clean even under magnification. Perfectly cut to bring out the fire and brilliance of this excellent material, this 4.65 ct gem will set up beautifully in a ring or pendant. Guaranteed natural and untreated. |
News from AJS and the Gems World
- Happy New Year 2016!
All the best for the new year to you and yours from all the staff at AJS Gems around the world. Thanks for making 2015 another successful year for us, and we look forward to working with you on your future gem projects.
- 'Crimson Flame Ruby' sells for $18.3 million at Christie's
An exceptionally rare 15 carat Burmese pigeon blood ruby named The Crimson Flame sold for $18.3 million at Christie’s Magnificent Jewels sale in Hong Kong in December. It surpassed its high estimate of $15 million and set a world auction record of $1.2 million per carat.
Ask the Gem Experts
Each month we answer questions from our customers. We welcome your questions and you can submit a question from our contact page.
I noticed that most of the rubies and sapphires in your collections are oval shape. Is it harder to find other shapes like square, round and triangular? Thanks for your time. BNR, Malaysia
Most corundum is alluvial in origin, and is found embedded in stream beds and beach sands. The rough stones tend to be rounded due to rolling around in oceans and rivers, and their outline shape is typically oval. Since ruby and sapphire are so valuable, gem cutters try to preserve as much of the rough material as possible. So that is why oval is the most common shape for corundum, especially in larger sizes. But you will see other shapes from time to time, especially cushions, hearts and pairs. Square shapes tend to be much less common.
All the best in gems,
Arnold, Rung & Ron
