January 2014 Newsletter: Spessartite Garnet from Nigeria

 

Spessartite Garnet rough from Nigeria

Spessartite Garnet
from Nigeria

 

Prior to the 1990's, spessartite garnet was so scarce that it was a gem known only to specialized collectors. But that changed with two important finds in Africa -- first with a small discovery in Namibia in 1991, then with a much larger deposit in Nigeria in 1999. The new supply of fine material enabled spessartite to enter the jewelry mainstream, where it was embraced for its vivid color and amazing fire.

Unfortunately the boom ended almost as soon as it started. By 2001 the new African desposits were mainly worked out and the finer material in the market today is mainly from material mined in the 1990's. As supplies have dwindled, prices have risen.

By chemical composition, spessartite is a manganese aluminum silicate and it is manganese that gives this gem its distinctive orange color. Spessartite is one of the ideochromatic gems, meaning it is colored by a fundamental element in its composition, rather than by impurities. If spessartite is mixed with almandine garnet -- the garnet variety containing iron -- it will tend towards more of a reddish-orange.

Spessartite Colors
Nigerian Spessartite range from pure orange to reddish-orange

Like other garnets, spessartite has very good hardness of 7 to 7.5, and is suitable for all kinds of jewelry. It is a very dense material, with a density rating of 4.12 to 4.18, denser than sapphire, ruby, zircon and diamond. So when buying spessartite it is important to check the size as well as the carat weight.

Prices on spessartite garnet vary according to quality and size. The main quality factors are color and clarity. The saturated pure orange is the rarest and most valuable. The bright yellowish-orange is the second most valuable color. The golden-orange and reddish-orange colors are generally less expensive, though these colors are also very attractive if the material is clean and the gems are well-cut.

Spessartites are generally cut similar to other colored stones, with ovals, cushions, rounds, trillions and emerald cuts being most common. The lack of pleochroism means that orientation is not a problem and the symmetrical shape of the rough generally provides good yields from rough to cut. Cabochon-cut spessartites are also seen on occasion, particularly with the Namibian mandarin spessartites, which tend to be more heavily included.

We acquired a good quantity of the Nigerian spessartite when it was still plentiful some years ago. But we have been unable to buy any high quality material at all for several years now. Almost all the new material we see -- whether from Nigeria, Namibia or Mozambique -- is filled with tiny bubble-like inclusions. 

For jewelry lovers, high quality Nigerian spessartite combines vivid color with exceptional brilliance. For gem collectors, there is still an opportunity to acquire these rare and valuable gems before they disappear from the market.

 

Notable Gems from the AJS Collection

This month we feature fine gems from Nigeria, including rare spessartites and tourmalines.

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

8.56 ct Spessartite Garnet, Nigeria

8.56 ct Spessartite Garnet from Nigeria

A pure mandarin orange in a large size with excellent clarity. Spessartites of this size and quailty are rarely found in today's market. 

See the video

8.27 ct Spessartite Garnet, Nigeria

8.27 ct Spessartite Garnet from Nigeria

A splendid example of the deeper red-orange spessartite, this square cushion is beautifully cut and very clean.

See the video 

20.98 ct Blue Green Touramline, Nigeria

20.98 ct Blue Tourmaline from Nigeria [SOLD]

A beautiful two tone gemstone. The color grades from pastel green blue to colorless at the very end  and the color mixes and moves as the stone moves. Loupe clean and precision cut.  A very pretty and most unusual gemstone that will sparkle in any setting.

4.09 ct Canary Tourmaline, Nigeria

4.09 ct Canary Tourmaline from Nigeria  [SOLD]

Yellow is one of the rarest of all tourmaline colors, with colors ranging from canary to gold, usually with just a touch of green. Most yellow tourmaline, like rubellite, have significant inclusions. This 4.09 ct round is a really top stone for yellow tourmaline -- vivid color with great brilliance, beautifully cut and very clean.

7.77 Rubellite Tourmaline, Nigeria

7.77 ct Rubellite Tourmaline from Nigeria  [SOLD]

A bright and lively rubellite with very good clarity for rubellite.  Excellent color saturation with red and pink flashes. Beautifully cut and polished.

 3.72 ct Bi-Color Tourmaline, Nigeria 3.72 ct Bi-Color Tourmaline from Nigeria  [SOLD]

This gorgeous watermelon tourmaline has saturated colors and great color separation. A brilliant gemstone superbly cut with a wonderful shape and lots of brilliance. This stone has been polished to a high luster with nice bright flashes of color. You will find it to be a very brilliant gemstone that will surely make a beautiful piece of jewelry.

 

News from AJS and the Gems World

  • AJS Gems in Tucson, February 2014

    We'll be exhibiting at the Pueblo Gem & Mineral Show in Tuscon from January 31 to February 12. The show is at the Arizona Riverpark Inn and you'll find us in room # 148. We'll be showing both rough and cut gems at the show. Look forward to seeing you there!

  • Gold decline the most in 30 years

    Gold prices fell more than 25 percent in 2013, ending a 13 year run of gains. It was the largest one year decrease in nearly three decades, with prices falling below $1,200 an ounce in December. Analysts say the crash in gold prices was due to the US Federal Reserve’s decision to reduce its bond purchase program. A steep fall in April also shook investors’ confidence in gold as a safe haven. Now some analysts are predicting a gold price around $1,050 by the end of 2014.

     

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.

What are my choices in green gems (not emerald)? Thanks very much for your advice! FN-S, UK

There are many choices in green gemstones, ranging from the chrome green of tsavorite garnet and chrome tourmaline to the emerald green of Imperial Jade, the apple green of peridot and the blue-green of apatite. For a complete list of green gemstones, see our Gemstone Color Chart.

 

What is the importance of density in gemstones? Are denser gems more durable? TJ, USA

There is really no correlation between density and durability. Some of the densest gem materials, such as cinnabar, hematite and cerussite are actually quite soft. Other dense materials, such as corundum and garnet, are very durable, as are some less dense gems such as quartz, beryl and tourmaline. Your main concern in understanding density concerns the size of gemstones relative to carat weight. Gems which are denser than diamond, such as garnet, zircon, sapphire, ruby and chrysoberyl, may appear smaller than expected for their carat weight, while lower density gems may appear larger. The rule for colored gems is always to check the size as well as the carat weight.

 

All the best in gems,

Arnold, Rung & Ron

 

 
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