The Perils of Paraiba-Jewelers Tears #2

September 23rd, 2010 by James L. Sweaney, CGA, FGA. GG
8.65 ct. Cuprian Elbaite, Before Heat Treatment

8.65 ct. cuprian elbaite tourmaline, before heat treatment

This tale of woe illustrates some of the risks and challenges we jewelers face in our fascinating business.

Last year, I had seen this lovely and large reddish purple tourmaline several times. Gem dealer Jack had tried mightily to tempt me with it, an unheated stone from the country of Mozambique in East Africa, an area that is producing controversial vivid blue and green tourmaline gems.

The controversy arises from new finds of tourmalines in both Mozambique and Nigeria that are very much like the famous and hugely expensive “Paraiba” tourmalines mined in and around the Paraiba state in Brazil. Discovered in the late 1980's, the Paraiba gems “electrified” the gem world with their previously unseen exotic colors, only to be followed by discoveries of similar material in Nigeria in 2001 and Mozambique in 2004. Like the original Paraiban material, some of these African tourmalines turn to vivid blues and greens when carefully heat treated.

The best of these rare colors have been described as “neon” and “electric”, with some top echelon gems fetching five figures per carat. This museum quality 10 carat stone (the picture certainly doesn't do it justice) was offered by a friend of the author last year for just under $200,000!

paraiba03

The controversy within the gem trade is one of nomenclature–whether the bright blue and green material from Mozambique and Nigeria can properly be designated and marketed as “Paraiba” tourmaline. Various gem labs and ruling bodies have taken up the question, conferences have been held, blogs and insults have flown back and forth, with no clear resolution. While the purists say that only gems mined in or near the Brazilian state of Paraiba can truly be labeled as “Paraiba” tourmaline, owners of the African gems often sell them as “Paraiba” tourmaline.

As we have seen with Burma ruby, Kashmir sapphire, and Colombian emerald, the power of name association creates a very strong brand that can be an extremely powerful marketing tool. It's especially useful when introducing a heretofore unknown product such as this type of tourmaline. Just google “paraiba tourmaline” and you'll see more than 35,000 results, many from mass market merchandisers like Home Shopping Network, Jewelry TV, and Ebay, selling everything from fine “Paraiba” gems for tens of thousands of dollars to “bargain” stones priced at tens of dollars.

One of the real problems is how to distinguish the Brazilian “Paraiba” gems from the African “Paraiba-like” stones. Color is not a reliable standard because there is so much natural variation in the desired hues, nor is size is a reliable test. Although stones mined in Brazil are usually smaller than the African goods, with few gems exceeding 3 carats, some Brazilian stones are good sized, witness the 10 ct. gem shown above.

These elbaite varieties of tourmaline are all characterized by traces of copper in their chemistry which can be reliably detected by spectroscopic analysis. Some of the gem labs have been designating type but not country of origin.  More recently, with the new material coming into the market place, the science has progressed to the point that there are reliable ways to distinguish country of origin. In general, the process is too technical and costly to be practical on an every day basis, especially for more ordinary stones.

The consensus has been to create a “Paraiba-type” classification, and a few of the labs have the skill and technology to issue reliable country of origin documents. While some gem dealers continue to use “Paraiba” as a trade name for bright blue to green copper bearing tourmalines, many of the more conscientious dealers avoid the controversy by selling their African gems as cuprian (copper bearing) tourmaline.

The use of this trade name brings up another issue– how much color should a stone have to be considered “Paraiba” or “Paraiba-type?” Many of the pale stones being marketed via Internet vendors at bargain prices have little resemblance to the vivid stones that originally created so much excitement.

The Lab Manual Harmonization Committee, representing GIA, AGTA, and other elite international gem labs, defines the color of Paraiba tourmaline in it's LMHC Information sheet #6 as “a blue (electric blue, neon blue, violet blue), bluish green to greenish blue or green elbaite tourmaline, of medium to high saturation and tone.”

Many of the bargain stones (and some not so bargain priced) we have seen could only be described as light in tone and weak to moderate in saturation. The question of whether a gem is Paraiba or Paraiba-type tourmaline is usually answered by the market price.

There is in fact a bifurcated market– the Gem Guide price book currently lists wholesale prices for 1 – 2 ct. cuprian tourmalines starting at $750-1,200/ct. for stones graded fine for overall quality, level 6-8 and $1200-1,800/ct. for extra fine gems, level 8-10. Stones with legitimate lab documentation as having originated in the Paraiba region of Brazil and having the signature bright blue to green colors wholesale  for the astronomical prices of $4,500-7,000/ct. for 1-2 ct stones graded fine, 6-8, $7,000-16,000/ct., for extra fine, 8-10!

This writer's advice is to carefully research and understand what the Paraiba-type colors truly are, and don't buy based solely on the trade name or lab document. It's best to buy gems like these from experts who truly understand this difficult market and can objectively evaluate the gem in question based on its merits.

Back to my story of the beautiful purple tourmaline from Mozambique. Having read the excellent article on Mozambique Paraiba-type tourmaline in the Spring 2008 issue of Gems and Gemology , I knew that this purple material could yield beautiful vivid blues and greens when carefully heated. When Jack offered me his moderately included stone again, this time at a rock bottom price, I bought it– it was a gorgeous deep reddish purple, well worth what he was asking.  Of course, I had the thought that it might be possible to heat treat it to a Paraiba-type color– even a moderately good color could quadruple what I had invested.

Later that spring, while working with a gem dealer from Germany whose family is very well connected to the centuries old gem trade in Idar-Oberstein, I showed him the stone and asked if he knew anything about heat treatment. While tourmaline was not his specialty, he assured me that he could easily get the stone treated in Germany. Though the stone was moderately included (perhaps why it had not already been heated?), he didn't think that would be a problem– his people heated similarly included stones “all the time.” So I took a big gulp, gave him the stone, and said “Go for it.”

It took about six weeks for the stone to make the round trip.  When I got the stone back and opened the paper, my heart sank–this is what I saw!

Oh no!

Oh no!

My Paraiba-type tourmaline is now not worthy of the name– just a faint hint of the desired color, and the inclusions really stand out. So we managed to transform a  richly colored gemstone into an essentially worthless rock, a ghost of it's former beauty. It's an example of  nature's booby trap or faulty heating technique– we'll never really know.

So the moral of the story is that sometimes you go for the brass ring and you miss! But that's what makes it exciting! Oh well, maybe I'll sell it on Ebay.

Naaah!

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