ChemicalProperties.UsingSchwarz’s (1990a)empirical
subdivision of low, medium, and high concentrations
of elements in emerald, the Fazenda Bonfim stones
show low Na and V, and moderate Cr, Fe, and Mg.
Notable are the relatively high K and low Li contents
compared to most emeralds from Zambia and Zim-
babwe, which also come from schist-type deposits
related to pegmatitic intrusions (table 3 and figure 20).
OnlysomeZambianemeralds showveryhighKvalues
combined with lower Li. A better separation between
the three localities can be made by plotting Ga versus
Li (figure 21). The Fazenda Bonfim emeralds have low
Li values and moderate-to-high Ga.
A clear separation between the three localities can
also be made by plotting data for K, Li+Cs, and Rb in
a ternary diagram (figure 22). The Fazenda Bonfim
emeralds showintermediateKandLi+Cscontents,and
stand out clearly from Sandawana emeralds and most
Zambian emeralds that show high Li+Cs, and from
some Zambian stones that are K-dominant. The Zim-
babweanemeralds canbedistinguishedfromZambian
material by their higher Rb content. When a beryl is
Li-rich, Cs typically appears in higher concentrations
as well(Bakakin and Belov, 1962). Generally speaking,
extremelyfractionatedrare-elementgraniticpegmatites
ChemicalProperties.UsingSchwarz’s (1990a)empiricalsubdivision of low, medium, and high concentrationsof elements in emerald, the Fazenda Bonfim stonesshow low Na and V, and moderate Cr, Fe, and Mg.Notable are the relatively high K and low Li contentscompared to most emeralds from Zambia and Zim-babwe, which also come from schist-type depositsrelated to pegmatitic intrusions (table 3 and figure 20).OnlysomeZambianemeralds showveryhighKvaluescombined with lower Li. A better separation betweenthe three localities can be made by plotting Ga versusLi (figure 21). The Fazenda Bonfim emeralds have lowLi values and moderate-to-high Ga.A clear separation between the three localities canalso be made by plotting data for K, Li+Cs, and Rb ina ternary diagram (figure 22). The Fazenda Bonfimemeralds showintermediateKandLi+Cscontents,andstand out clearly from Sandawana emeralds and mostZambian emeralds that show high Li+Cs, and fromsome Zambian stones that are K-dominant. The Zim-babweanemeralds canbedistinguishedfromZambianmaterial by their higher Rb content. When a beryl isLi-rich, Cs typically appears in higher concentrationsas well(Bakakin and Belov, 1962). Generally speaking,extremelyfractionatedrare-elementgraniticpegmatites
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