The anhydrous amphibole ungarettiite from the Woods mine, New South Wales, Australia
Kawachi, Yosuke; Coombs, Douglas S.; Leake, Bernard E.; Hinton, Richard W.
European Journal of Mineralogy Volume 14 Number 2 (2002), p. 375 - 377
published: Mar 22, 2002
ArtNo. ESP147051402013, Price: 29.00 €
We report ungarettiite from the Woods mine, New South Wales, Australia; this is the second known occurrence. Electron microprobe and ion-probe analyses show it to be very close to end-member composition, NaNa2Mn2+2Mn3+3Si8O22O2. We record the first direct determination of H2O (< 60 ppm) in this anhydrous amphibole, together with F (53 ppm) and Cl (5 ppm), giving (OH+F+Cl) a maximum of ~0.01 sites per formula unit. Li, ~4 ppm, and other trace elements are reported, most of them for the first time. Like various associated minerals, it contains very low to negligible Al, Mg, and Ca. Fe varies from below detection by EMP analysis to about 0.35 atoms p.f.u. Fe is strongly partitioned into any associated manganian aegirine.