MATERIALS AND METHODS
For this study, we examined 41 samples from Fazenda
Bonfim, including 11 pieces of emerald rough that were
transparent and suitable for faceting and 15 thin sections made from emerald-bearing rock; all of this material
was collected by author JCZ during his visit to the mine.
Parallel plates were cut and polished from three of the
rough pieces for spectroscopy, whereas the thin sections
were used only for studying inclusions in the emerald
grains. In addition, 14 faceted and one cabochon-cut
emerald, ranging from 0.17 to 3.89 ct, were obtained
from Mineração Vale Verde Ltd. for this investigation