March 2015 Newsletter: African Tourmaline

Tourmaline has become one of the most popular of all colored gemstones. Collectors are attracted by its huge range of colors and its very good gemstone characteristics -- tourmaline is reasonably hard (7 to 7.5 on the Mohs hardness scale), and durable enough for all kinds of jewelry. High quality tourmalines have excellent transparency and an attractive vitreous luster. It is also still a very affordable gemstone, particularly in larger sizes, since the per carat price for tourmaline doesn't increase radically with size like the prices for sapphire and ruby.

Rubellite Tourmaline, Nigeria Blue-Green Tourmaline, Nigeria Fancy Tourmaline, Nigeria Bi-Color Tourmaline, Mozambique Chrome Tourmaline, Tanzania

Unlike many gemstones, deposits of tourmaline have been found all over the world, from Asia to the Americas. Historically the most important deposits were in Sri Lanka, Brazil and the USA. But today no location produces such a variety and quantity of fine tourmaline as Africa.

The two largest producers of fine tourmaline are currently Mozambique in east Africa and Nigeria in west Africa. Both countries have produced a wide range of colors, ranging from pink to blue and greens to bi-colors and fancies. They are also known for producing fine specimens of the rare and valuable rubellite and paraiba varieties.

The other notable source for tourmaline is Tanzania in east Africa. Though Tanzania does not produce a great variety of tourmaline, it is the only source for the rare green tourmaline colored by traces of chromium and vanadium. Like tsavorite, fine chrome tourmaline tends to a pure forest green with slightly yellowish to bluish secondary hues. Due to its rarity, chrome tourmaline is substantially more expensive than ordinary green tourmaline, though not nearly as expensive as tsavorite garnet. Like rubellite and paraiba, chrome tourmaline is highly sought after by tourmaline collectors.

Other regions in Africa occasionally produce notable tourmalines. Zambia, known best for emerald and amethyst, has produced some fine red and yellow tourmalines, while Malawi has produced some rare yellows known in the trade as canary tourmaline. There are also believed to be substantial tourmaline deposits in Madagascar, but thus far mining efforts have tended to focus on the more valuable ruby and sapphire deposits there.

 

Notable Gems from the AJS Collection

This month we feature fine African tourmalines from Nigeria, Mozambique and Tanzania.

Click on a photo to see the details for the item.

5.02 ct Pink Tourmaline, Mozambique

5.02 ct Pink Tourmaline from Mozambique

A vivid hot pink tourmaline from Mozambique in a perfect ring size. This rare gem has amazing saturation. Guaranteed natural and untreated.

 

4.88 ct Blue Green Tourmaline, Mozambique

4.88 ct Blue Green Tourmaline from Mozambique

This stunning teal gem from Mozambique has everything we look for in a fine tourmaline -- vivid color, exceptional clarity, and a precision cut with excellent luster. Guaranteed natural and untreated.

 

9.35 ct Yellow Tourmaline, Nigeria

9.35 ct Yellow Tourmaline from Nigeria

Yellow is one of the rarest colors for tourmaline, and usually found only in smaller sizes. This golden-yellow 9 carat stone is very clean and well cut, a true collectors gem. Guaranteed natural and untreated.

12.79 ct Bi-Color Tourmaline, Mozambique

12.79 ct Bi-Color Tourmaline from Mozambique

A beautiful bi-color tourmaline from Mozambique in a large size. This unique gem is 70 percent bright yellowish green and 30 percent blue-green. Completely clean and perfectly cut, this 30 mm long octagon will make an elegant pendant. Guaranteed natural and untreated.

See the video

7.09 ct Fancy Tourmaline, Nigeria

7.09 ct Fancy Tourmaline from Nigeria  [SOLD]

An intense pink-red with just a touch of orange, this tourmaline is a gorgeous stone, bursting with color from all angles. Excellent cut and proportions bring out the maximum brilliance from this fine material. Guaranteed natural and untreated.

See the video

2.00 Chrome Tourmaline, Tanzania

2.00 ct Chrome Tourmaline, Tanzania  [SOLD]

A superb chrome tourmaline with a bright open color and full fire. Very clean and well-cut, this is as fine a chrome tourmaline as you will see in the 2 carat size. Guaranteed natural and untreated.

 

News from AJS and the Gems World

  • Sotheby's to Auction 100 carat Emerald Cut Diamond

    Sotheby’s will auction a 100 carat emerald-cut diamond at its Magnificent Jewels auction in New York on April 21st. The 100.2 carat, D color, Internally Flawless, Type IIa stone has an estimate of $19 to $25 million. The auction house said this is the largest, perfect emerald-cut diamond to be offered at auction. The diamond comes from a piece of rough weighing more than 200 carats and was mined by De Beers in southern Africa
    .

  • SSEF Announces New Lab in Basel

    SSEF, the laboratory of the Swiss Gemmological Institute, has opened a new state-of-the-art laboratory in Basel as part of an expansion of their research, education and grading services. The new lab features the Automated Spectral Diamond System, developed by SSEF to analyze large quantities of diamond melee for simulants, synthetics and HPHT-treated diamonds.

 

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 have made many purchases from AJS Gems in the past and have been completely satisfied with every aspect of the experience. However, I have one nagging question. Do you take political and social concerns into consideration when sourcing your gem suppliers? I am specifically addressing areas where 'conflict minerals' or 'blood gems' are sourced. I would truly appreciate having a response from you. NS, Canada

Thus far there is no protocol in the colored gems world similar to the Kimberely Process for diamonds (which certifies diamonds as "conflict-free"). So we have to check the sources for all our gems ourselves. As a matter of principle would not buy any gems whose proceeds are being using to fund conflicts, and we try whenever possible to buy directly from miners rather than middleman so that the profits go to the people who produce the material. 

 

I read with interest your tanzanite article in your February newsletter. Could you tell me if unheated tanzanite is more valuable than heated? MS, USA

For violet-blue tanzanite, there is no really no price difference in the market between heated and unheated gems. The reason is that the saturated violet-blue color is produced by low temperature heating, and there are virtually no unheated tanzanites with this vivid color. In the case of rare fancy tanzanite colors, such as pink, these gems are almost always unheated, since these colors only occur naturally. 

 

All the best in gems,

Arnold, Rung & Ron

 

 
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