Welcome to AGTA GTC's Laboratory Update for May 18, 2006

In this message

  1. AGTA GTC Mobile Laboratory at Las Vegas
  2. The Question of Paraíba
  3. About the LMHC
  4. New Service – Identification Reports for Paraíba Tourmaline
  5. Upcoming Lectures by AGTA GTC Staff

Current turnaround time at the AGTA GTC
5–7 Business Days
Submit your gemstones before May 23, 2006 to have them ready for the Las Vegas JCK Show.
If needed, we can deliver them to you at the show.

The AGTA GTC Mobile Laboratory in Las VegasAGTA in Vegas poster
Once again, the AGTA GTC will be participating in The JCK Show – Las Vegas 2006, offering a range of gemological services, such as:

  • Identification reports for all kinds of gemstones, including the identification of clarity enhancement fillers.
  • Country-of-Origin reports for ruby, sapphire and emerald.

    The AGTA Pavilion has special dates and times, opening and closing one day before the main JCK show. The AGTA GTC Mobile Laboratory, located in the AGTA GemFair Cultured Pearl & Jewelry Pavilion, is open Friday, June 2nd to Tuesday, June 6th. Hours are 10:00 AM to 6:00 PM on June 2nd and 9:00 AM to 6:00 PM from June 3rd–6th. The AGTA GTC Mobile Laboratory is planning to deliver the reports to clients within 1–2 days and services will be available during normal show hours.
     But even better than submitting gemstones during the show is to submit them to the AGTA GTC prior to the show, where you can enjoy our normal rates (gems tested at the show will incur a slight surcharge). By doing so, you'll have the gemstones in your showcase ready for sale with reports. Gemstones submitted by Tuesday, May 23rd, will be returned to you at the show. Hurry up and have your gemstones tested today!

Show fee schedules

Shwewar Yee at the Las Vegas JCK Show
The AGTA GTC's Shwewar Yee taking in gemstones at the 2005 Las Vegas JCK Show.

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The Question of Paraíba

In 1989, unusually vivid tourmalines from the northeastern state of Paraíba, Brazil, appeared on the international gemstone market. Colors ranged from blue to green, with the most desired being a "neon" greenish blue (Figure 1).
    These Paraíba-type tourmalines belong to the elbaite species, but contain manganese (Mn) and copper (Cu) with a Cu content of up to 2.30 wt% CuO, as well as bismuth (Bi). Copper was quickly labeled as the principle cause of the rich color.
    From the beginning, the trade labeled these Paraíba tourmalines (Fritsch et al., 1990). The name quickly caught on and is now mentioned as a valid trade name in the CIBJO Rules. The CIBJO definition from 1999 mentions:

Mineral substance: Tourmaline (group of)
Variety/type:   Green to blue, due to copper
Commercial name: Paraíba Tourmaline

Paraiba tourmaline colors

Figure 1.
Range of tourmalines from Paraíba, Brazil.  Fashioned as "Torus Rings" by American carver, Glenn Lehrer. Photo by Robert Weldon.

     Meanwhile, more locations of Cu-containing tourmalines were discovered. The first was in Brazil's Rio Grande Do Norte state, just north of Paraíba state. This new find was also described as "paraíba tourmaline."
     In 2001, yet another Cu-bearing tourmaline locality was discovered, this time in Nigeria (Smith et al., 2001). The Nigerian gemstones are generally not as vivid as those from Brazil. Chemically, the Nigerian material can also be easily distinguished by its lead content, in addition to copper and manganese. But according to the CIBJO rules, it fits the paraíba definition, and they have been sold extensively under that moniker.
    A further complication arose in 2005, when paraíba-like tourmalines from Mozambique entered the market (see Figure 2) (Abduriyim & Kitawaki, 2005). Some of this material is much closer in color to the original Paraíba tourmaline, and often not distinguishable by the naked eye. The chemical composition is much more complex with varying amounts and large ranges of Mn, Cu, lead (Pb), and Bi. A large number of these tourmalines do not contain any Pb, and may easily overlap with properties of the Brazilian Cu-bearing tourmalines. The trade quickly began referring to these gems as "paraíba tourmalines from Mozambique."
     This led to heated discussion among laboratories and the trade, coming to a head at the international Gemstone Industry Laboratory Conference (GILC) in Tucson in February 2006. At the Conference it was suggested that the term "paraíba tourmaline" be adapted as a variety name, rather than a geographic origin. If origin was requested, laboratories could then prepare an origin report (where possible). This suggestion was countered by a large faction of dealers who did not see this as a viable solution, arguing that origin is not a valid criteria for a variety name.

Mozambique Paraiba Tourmalines

Figure 2. Range of color observed in Cu-bearing tourmaline from Mozambique. The top left sample weighs 5.50 ct and is 11.44 mm in length (Courtesy of Joe Menzie). The 4 oval large samples range from 2.75 ct to 4.21 ct (courtesy of Rick Krementz), and the small samples range from 0.07 to 0.92 (donation from F. Bank of Gebr. Bank, Idar-Oberstein). (Photo Min Htut, AGTA-GTC)

Defining varieties
Traditionally, minerals as well as mineral and gemstone varieties received their name either as a reference to the place where they were first encountered (St. Cristobal, Mexico for cristobalite or Tsavo, Kenya for tsavorite), in recognition of famous mineralogists or gemologists (haüyne; goethite; liddicoatite; pezzottaite), by phenomena (fluorite because of its strong fluorescence in UV light; moonstone; sunstone), by chemical composition (cuprite; chrome tourmaline), and very often by the color, although this doesn't always show up in the name (ruby, sapphire, emerald, aquamarine, rubellite).
    We know a ruby is red, but we also know that there are more red gemstones. Had it not been for new findings along the way that allow us to separate minerals and gemstones from each other, all red gemstones would still be called carbuncle. When pezzottaite was first discovered, it was misidentified as "pink beryl." The properties differed slightly from beryl, but only chemical and structural analysis proved this gemstone to be a new mineral.

The Paraíba debate
Tourmaline is a group of mineral species including elbaite, liddicoatite, uvite, dravite, buergerite, olenite, and schoerl. These are split up in variety and trade names which are internationally accepted, such as rubellite or chrome tourmaline (much of this type is actually colored by vanadium instead of chromium). Now we have an elbaite species of an electrifying blue to green color that contains copper and was first mined in Paraíba, Brazil. What could be more obvious than calling this special material "paraíba tourmaline?"
     Many of the Brazilian "paraíba" dealers actually went to Mozambique and Nigeria to stock up their "Brazilian" material. The color range of the material is quite similar (Photos 1 and 2). We can only hope that Brazilian dealers let their clients know that their material is actually from Mozambique.
     Looking at the chemical data, the differences are sometimes so small and properties overlapping that it may not be possible to give an origin at all for the occasional stone. Looking at the colors, the best samples from Nigeria or Mozambique had colors that were as vivid as the ones from Brazil. What was the solution? Go with the obvious? Call all copper-containing tourmalines paraíba, no matter where they come from, and specify an origin (Brazil, Nigeria, Mozambique)? Or omit the word paraíba altogether, and call them cuprian blue elbaite tourmaline?

Color before chemistry?
These challenges have kept the laboratories of the international Laboratory Manual Harmonization Committee (LMHC), of which the AGTA-GTC is a member, busy for several months before a consensus was finally reached in April. New gemstone identification reports will call all copper containing elbaite "paraíba tourmaline," regardless of their origin. This is consistent with current trade practice. To highlight the fact that these gemstones may come from different origins, however, there will be a comment stating that the description is a variety name only derived from the locality in Brazil where it was first mined. The information sheet, which will be on our website after June 1, contains additional information regarding the color and the chemical composition of these gemstones.
     The AGTA-GTC is going a step further. Future identification reports for copper containing tourmalines will now read:

Species: NATURAL ELBAITE TOURMALINE
Variety:   PARAIBA TOURMALINE
Origin: NOT DETERMINED
Comments: The variety name paraíba is derived from the locality in Brazil where it was first mined. Its geographical origin has not been determined and therefore could be from Brazil, Mozambique, Nigeria or another locality.

     Where origin determinations are possible and the client demands an origin, the appropriate origin replaces the words NOT DETERMINED, and the sentence in comments is omitted.
     Samples of the new reports can be viewed here:

References

  • Fritsch, E., Shigley, J.E., Rossman, G.R., Mercer, M.E., Muhlmeister, S.M. & Moon, M. (1990) Gem-quality cuprian-elbaite tourmalines from Sao Jose da Batalha, Paraíba, Brazil. Gems & Gemology, Vol. 26, No. 3, Fall, pp. 189–205.
  • Smith, C.P., Bosshart, G. & Schwarz, D. (2001) Gem News International: Nigeria as a new source of copper-manganese-bearing tourmaline. Gems & Gemology, Vol. 37, No. 3, Fall, pp. 239–240.
  • Abduriyim, A. & Kitawaki, H. (2005) Gem News International: Cu- and Mn-bearing tourmaline: More production from Mozambique. Gems & Gemology, Vol. 41, No. 4, Winter, pp. 360–361.

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About the LMHC
On our reports and in our newsflashes, you may frequently see references to the LMHC. LMHC stands for Laboratory Manual Harmonization Committee, and is a group of seven laboratories that work together on harmonization of report language. The LMHC was founded in 2002, after an annual meeting in Tucson, where the industry and laboratory representatives meet and discuss current issues. One such issue was that the various laboratories had different ways of expressing treatments, and often different standards about quantification as well.
    Members of the LMHC now meet several times throughout the year to discuss harmonization of report language and how to address current issues. The laboratories currently involved are: the AGTA Gemological Testing Center for USA, CISGEM for Italy, GAAJ (Gemmological Association of All Japan) for Japan, GGL (Gübelin Gem Lab) for Switzerland, GIA for USA, Switzerland and Thailand, GIT (Gemmological Institute of Thailand) for Thailand, and SSEF Swiss Gemmological Institute for Switzerland. Each laboratory sends one representative to these meetings.
    Most of the laboratories that comprise the LMHC report to a governing body, such as our AGTA Board of Directors, which typically represents the colored gemstone and cultured pearl industry in their respective countries.
    When a decision is taken concerning report wording, an Information Sheet is drafted, and the various laboratories present it to their boards for approval. Often, the approval does not come in the first round, and the members of the LMHC go back to the table and see where compromises can be made. This process is repeated until a consensus is reached, the information sheets are published, and each lab implements the new report wording on their existing reports.
    Considering the range of laboratories involved, from producing countries such as Thailand or consuming countries such as Switzerland or Japan, it becomes clear that every country could have its own preferred standards, and that these standards could quite possibly be far apart from each other. While clients across the globe may not universally support the language that flows from this harmonization process it is certainly preferable to a marketplace where disparate report language can create confusion and frustration.  Compromise, thorough discussion, and careful evaluation that lead to solutions that everyone can live with remains the primary goal of the LMHC.

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New Identification Reports for Paraíba Tourmaline
Beginning May 15th, the AGTA GTC will adopt a new policy involving identification reports for paraíba tourmaline. Previously, our reports identified this type of material as "cuprian elbaite tourmaline" and if requested, an origin report could be issued.
    After extended discussions with clients, members of our industry and other laboratories we are instituting a new policy whereby all cuprian elbaite tourmaline will be identified on our reports as “paraíba tourmaline" (see The Question of Paraíba). This policy is consistent with widespread industry practice and has also been adopted into the guidelines of the LMHC (see About the LMHC). Samples of both origin and non-origin reports can be seen here:

     The AGTA GTC now issues three types of tourmaline reports as follows:

  • Standard ID Report (beginning at $160 keystone for members).
  • Paraíba Analysis to determine if the gemstone meets paraíba standards
    An additional fee applies, similar to that charged for color analysis of padparadscha sapphire (beginning at $120 keystone for members).
  • Paraíba Analysis with Origin
    The fee for origin analysis applies (beginning at $320 keystone for members).

 

To introduce this new product, the AGTA GTC will run a special promotion at the AGTA GemFair during the JCK Las Vegas Show. Each client who submits a gem for testing at the show will receive a voucher for a 20% savings on up to three paraíba tourmaline reports submitted any time during the month of June. These vouchers are only for paraíba tourmaline reports and are limited to three per client.

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Lectures in Australia
AGTA GTC Chief Gemologist John Koivula will be giving a series of eight lectures throughout Australia over a period from May 13–24, 2006. In Sydney, John will be the keynote speaker at the Gemmological Association of Australia's 2006 National Conference from May 19–21.

Lectures in Las Vegas
At the upcoming Las Vegas JCK show, AGTA GTC Lab Director Lore Kiefert will participate in a panel discussion on Colombian emeralds as follows:

Colombian Gem News
Moderator: Stuart Robertson (Gemworld International)
Panelists: Loretta Castoro; Dr. Lore Kiefert (AGTA GTC); Ron Ringsrud (Ronald Ringsrud Co.); Robert Weldon (GIA)
Thursday, June 1, 2006
10:30–11:30 AM

Recently, this group of panelists closely witnessed mining and treatments of Colombian gemstones. What they discovered was a new generation of Colombian mine owners who have formed strategic alliances aimed at benefiting the region as a whole. Through cooperation, this group hopes to add value and restore confidence in the Colombian emerald market by implementing Fair Trade principles and product certification with meaningful disclosure. The Colombian market is actively pursuing international buyers by establishing an emerald center near the airport in addition to the major trading center in Bogota's business district. Hear from a reporter, a value-added specialist who is a former colored gemstone buyer for Tiffany, the head of the AGTA GTC, and a dealer specializing in Colombian gemstones in this session.

She will also deliver a lab update:

AGTA GTC Update
Dr. Lore Kiefert (AGTA GTC)
Friday, June 2, 2006
10:30 –11:30 AM

The AGTA Gemological Testing Center encounters unusual gemstones in the midst of more routine gemstone submissions. Learn what AGTA is watching for in the Center now and how GTC works on identification, treatments, and country of origin.

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The AGTA Gemological Testing Center provides the industry and the public with a complete range of lab services including gemstone identification, origin determination and pearl identification. Located in New York City, the laboratory is equipped with the latest, technologically advanced, investigative equipment. The AGTA GTC is committed to providing excellent service, superior value and outstanding quality. A complete list of services and detailed pricing information is available on our website, www.agta-gtc.org. Please contact us with any questions.


American Gem Trade Assocation Gemological Testing Center
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New York, NY 10017, USA
Tel: 212-752-1717; Fax: 212-750-0930
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