14/06/2006

“Paraiba”-tourmaline research completed – reporting policy of GRS

GRS announces that it has completed its research on “Paraiba tourmalines”. Paraiba tourmaline is a Cuprian-Elbaite of “neon-colors” of pastel greenish-blue to blue hue from the origin of Brazil (lit. 1). Such tourmalines, however, have recently become known from various other origins. The trade had to settle the question whether these tourmalines from these different origins can be distinguished and whether tourmalines from Mozambique or Nigeria should be called “Paraiba tourmalines” or not.
Our research on samples from Nigeria, Mozambique and Brazil (various mines including those from Paraiba) confirmed a recent study (lit. 2) that a distinction can be made. However, our conclusion on the terminology regarding Species and Variety name is different. We reject the proposal (lit. 2) to summarize all tourmalines from 3 different origins as “Paraiba tourmalines” as shown below:

Species: Elbaite
Variety: Paraiba tourmaline
Comment: The name “Paraiba tourmaline” is derived formt he locality where it was first mined in Brazil.

At GRS, we do not follow this terminology, but have established the following Gemstone Report types for tourmalines for the 3 different origins.

 

“Paraiba”-Tourmaline Reporting Policy of GRS:

  1. Species and Variety names are not changed, e.g. Tourmaline (Species) and Cuprian Elbaite (Variety) remains.
  2. The name Paraiba does not enter the variety name.
  3. Origins determination appear always (if possible to determine). It is also pointed out that Paraiba is not the only occurrence in Brazil. Different mines in Brazil are not differentiated on the report. They are summarized under the Brazil origin, while Paraiba is highlighted in “bold”, the other mines of Brazil are mentioned as well, see sample. This allows the consumer to orient himself in relation to an established name in the trade and to realize that his “Paraiba tourmaline” may actually come from “Rio Grande do Norte”.
  4. For other tourmalines than those of Brazil (e.g. Mozambique”), the name “Paraiba” appears only in the color description section, with a remark that says that the name “Paraiba” appears, because the color is similar and due to “Copper” such as those found in tourmalines from Paraiba (see comments on report sample). E.g. neon-blue tourmalines such as those from Afghanistan without concentrations of copper (like those samples in our collection) will not be called “Paraiba” -type neon-colors, but they are labeled “neon-colors”. However, those from Mozambique are labeled “Paraiba”-type Neon-Colors.
  5. Heat-enhancements are determined and mentioned of course. If they cannot be determined, it wills say on the report, that the “Application of heat currently undetermined (commonly enhanced by heat).

Our terminology targets the following objectives:

  1. Protect the traditional “collectors”, “connoisseurs” or dealers for their past investments in “Paraiba” tourmalines if they wish to have their goods to be related to its origin in their marketing concept.
  2. Provide the client the choice of making up his mind whether a “Paraiba-type neon-color” from Mozambique should be handled at the same level like those from Brazil, rather than making this choice on the level of the laboratory.
  3. Establish a correlating link between Cuprian Elbaites from Brazil, Mozambique and Nigeria on the basis of color only in using the name “Paraiba”, while the origin determination is separated. This reflects recent market trends.
  4. Preventing potential trends in the market that tourmalines are labeled as “Paraiba tourmalines”, are eventually marketed as coming from Paraiba (Brazil), when in effect they are from Mozambique for example.

Literature:

Lit 1: Wilson, W.E. (2002): Cuprian Elbaite from the Bathalha Mine, Paraiba, Brazil, Mineralogical Record, vol. 33, no.2, page 127-137.

Lit.2: Abduriyim A., Kitawaki H., Furuya M. and Schwarz D. (2006): “Paraiba”-type Copper-bearing Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting by LA-ICP-MS, Gems&Gemology, Spring Issue, page 4-21.

 

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