|
|
|
Fig. Par 75a Variation in Cu-, Mn- and Bi-concentrations. The color-zoning can be correlated with the chemical variations as measured by LA-ICP-MS (in ppm) and by ED-XRF (Fig. Par74, 75a-b and 76a-f).
Low Cu-concentrations are found in the purple core. They increase towards the blue part of the crystal and decrease towards the rim.
Mn-concentrations are high in the purple core and decrease towards the blue color zone. In the rim, they increase to the highest measured value in the entire profile. Highest Mn/Cu-ratios are found in the purple core and in the outer rim (Fig. Par75b).
Lowest Bi-concentrations are found in the core of the crystal. Towards the rim, the Bi-concentrations constantly increase. Highest Bi/Mn-ratios are found in the transition from the blue to the green color zone.
The trend of variations in Bi-concentrations is opposite to the trend observed in tourmalines from Brazil (See Fig. Par59a, 62a and 66a).
In the outer dark green rim of the crystal, the Mn-concentrations increase along with Fe-concentrations (not measured by LA-ICP-MS, ED-XRF data, see Fig. Par74).
Fig. Par75b Variation in Mn/Cu-, Bi/Cu- and Pb-Be-ratios Pb/Be-ratio decrease toward the rim and an opposite trend is observed for the Mn-Cu-ratio and Bi/Cu-ratio. They increase towards the rim. Note a sudden change of ratios is found at the transition zone from the purple core to the “neon”-blue color zone.
|
LA-ICP-MS Analysis Profiles of Multicolored Tourmaline from Mozambique
