Mg-Pb-Zn Chemical Evolution Trends in Tourmalines
from Mozambique and Brazil (Pb-Mg-Zn-Diagram)
 

Fig. Par91a-d

Triangular plots of Mg-Pb-Zn (Fig. Par91a) and Mn-Bi-Cu (Fig. Par91c) of chemical compositions in multicolored copper-bearing tourmaline from Mozambique and Brazil are shown (LA-ICP-MS analysis, in µg/g). 5 chemical profile analysis of tourmalines from Brazil and 2 from Mozambique are shown in the same diagrams. Chemical compositions from the core to the rim are mapped (A-H). For each studied sample, a chemical trend is obtained that shows the chemical variations of the tourmalines from the core to the rim (“Chemical evolution trends” marked with red and green lines, Fig. Par91b and Par91d). The sample number is indicated.

Different chemical trends were found for tourmalines from Mozambique and Brazil.

As sown in Fig. Par91d, tourmalines from Mozambique evolve towards the Mg-corner.

Brazilian tourmalines show a relative trend towards higher Zn-concentrations during their growth. A 2-step trend was found.

A chemical trend towards higher Pb-concentrations is followed by a trend towards higher Zn-concentrations.