Japan

Fukuaka Prefecture
Nagatare Pegmatite


elbaite-rossmanite

Tourmaline from the Nagatare Pegmatite in which the composition varies in the proportions: elbaite > rossmanite >> fluor-elbaite.
The chemical composition of this specimen is shown in Table 1 of Shirose and Uehara (2013)

Image courtesy of Seiichiro Uehara, Kyushu University.



 
Rossmanite occurs in a complex Li-Cs-Ta enriched pegmatite near the city of Nagatare, Japan. The compositions are mostly in the elbaite field and just barely cross over into the rossmanite field.

Composition

A typical rossmanite composition is
X([]0.52Na0.47Ca0.01) Y(Li1.20Al1.72Mn0.07Fe0.01Zn0.02) ZAl6.00 (BO3.00)3.00  Si6.00O18.00   [(OH)3.88F0.12]


Composition

References:

Shirose Y, Uehara S (2013) Li tourmaline from Nagatare, Fukuoka Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 108, 238-243.

last upgraded: 14-Aug-2014