Mozambique
near Mavuco
Muva
Gem quality rossmanite occurs in crystals of mixed elbaite-rossmanite
compositions. At this locality, there is
no correlation between the color of the sample and the species of
tourmaline. Pink, pale yellow and yellow-green crystals have been shown
to be rossmanite by electron microprobe analysis (Laurs et al. 2008; Simmons et al. 2011).
In their study, Simmons et al. (2011) also found flourine-dominant
yellow rossmanites that corresponds to the hypothetical mineral species,
fluor-rossmanite.
This
phase has never been fully studied and characterized to the point that
it could be submitted to the IMA for consideration as a new mineral
species.
X-site compositions of
rossmanite and representative elbaite tourmalines
from the Muva, Mozambique, locality as reported in Laurs et al., 2008.
"Fluor-rossmanite" compositions in the flourine-rich yellow tourmalines from Muva. (After Figure 8 in Simmons et al, 2011)
References:
Laurs BM, Zwan JC, Simmons WB, Falster AU (2008) Tourmaline
from Muva, Mozambique. Gems & Gemology, 44, 273-275.
Simmons
WB, Falster AU, Laurs BM (2011) A survey of Mn-rich yellow tourmaline
from worldwide localities and implications for the petrogenesis of
granitic pegmatites. The Canadian Mineralogist 49, 301-319.
last updated 17-Mar-2017