Paraiba Research Update: An elemental Analysis of Paraiba Tourmaline ...
Figure 6: Scatter plot of Cu-Ga-Sn concentrations in Cu-Mn bearing tourmalines from Brazil and Mozambique. Blue and red dots are extracted from SSEF’s database for Paraiba tourmalines from Brazil and Mozambique. The blue diamonds with yellow outline indicate samples originating from the field trip to Paraiba, Brazil.
Geographic Origin Determination of Paraíba Tourmaline
2017年5月8日 · Copper-bearing gem tourmaline, known as Paraíba tourmaline after the location of its original discovery, is prized for its vivid blue to green color. This article explains GIA’s use of quantitative chemical analyses to distinguish samples from Brazil, Nigeria, and Mozambique.
Geographic Origin Determination of Paraiba Tourmaline
2019年2月1日 · Paraíba-type tourmalines consist primarily of elbaite (or fluor-elbaite, but simply mentioned as elbaite in the text), and secondly of liddicoatite (currently known as fluor-liddicoatite but...
It measures approx. 7.30 x 5.24 x 3.31 mm and changes from blue-violet to green blue. Figure 1: Paraiba tourmaline from the Batalha Mine in Paraiba, Brazil with a colour change from day light (left) to incandescent light (right).
Geographic Origin Determination of Paraiba Tourmaline
2019年2月1日 · Unusually vivid tourmalines from the state of Paraiba, in northeastern Brazil, have attracted great interest since they first appeared on the international gem market in 1989. This article describes …
UV-Vis-NIR absorption spectra are shown for various
UV-Vis-NIR absorption spectra are shown for various colors of unheated faceted Cu-bearing tourmaline from Mozambique. All the spectra have two distinctive broad bands at ~700 and ~900 nm...
Copper-bearing tourmaline, also known as Paraíba-type tourmaline (or paraiba tourmaline; LMHC 2012), is one of the most sought-after and appreciated coloured stones in the trade. This is mostly due to its vivid colour, which in the best cases is described as ‘neon’ or ‘electric’ blue. However, Cu-bearing tourmalines are found in many
In this article, we describe the geology of the Mina da Batalha and associated alluvial/eluvial deposits, and also update the gemology of “Paraíba” tourmaline. Brief descriptions of cuprian elbaites from two other pegmatite mines (Mulungu and Alto dos Quintos) in Rio Grande do Norte State also are included.
Major- and Trace-element Composition of Paraíba-type Tourmaline …
In Brief • Geographic origin can have a significant impact on the value of Paraíba tourmaline. • Quantitative chemical analysis with LA-ICP-MS provides a robust tool for origin determination. • The trace elements Cu, Zn, Ga, Sr, Sn, and Pb are the most useful discriminators for Paraíba tourmaline origin.
spectra were collected from 1200 to 100 cm–1 Raman shift. They revealed two distinctly different spectra (Fig. 2), which could be attributed to tourmaline and lepidolite, a lithium bearing mica (phyllosilicate), known mostly from pegmatites in purple to …