@article{KutzschbachWunderKrstulovicetal.2016,
  author    = {Kutzschbach, Martin and Wunder, Bernd and Krstulovic, Marija and Ertl, Andreas and Trumbull, Robert B. and Rocholl, Alexander and Giester, Gerald},
  title     = {First high-pressure synthesis of rossmanitic tourmaline and evidence for the incorporation of Li at the X site},
  series = {Physics and chemistry of minerals / in cooperation with the International Mineralogical Association (IMA)},
  volume    = {44},
  journal   = {Physics and chemistry of minerals / in cooperation with the International Mineralogical Association (IMA)},
  publisher = {Springer},
  address   = {New York},
  issn      = {0342-1791},
  doi       = {10.1007/s00269-016-0863-0},
  pages     = {353 -- 363},
  year      = {2016},
  abstract  = {Lithium is an important component of some tourmalines, especially in chemically evolved granites and pegmatites. All attempts at synthesizing Li-rich tourmaline have so far been unsuccessful. Here we describe the first synthesis of rossmanitic tourmaline at 4 GPa and 700 degrees C in the system Li2OAl2O3SiO2B2O3H2O (LASBH) from seed-free solid starting materials consisting of a homogenous mixture of Li2O, gamma-Al2O3, quartz and H3BO3. The solid run products after 12-day run duration comprise rossmanitic tourmaline (68 wt\%), dumortierite (28 wt\%) and traces of spodumene (3 wt\%) and coesite (1 wt\%). Tourmaline forms idiomorphic, large prismatic crystals (30 X 100 mu m), which are inclusion free and chemically unzoned. The refined cell dimensions of the tourmaline are: a = 15.7396(9) angstrom, c = 7.0575(5) angstrom, V = 1514.1(2) angstrom 3. Conventionally, the Li+ ion is assumed to exclusively occupy the octahedral Y site in the tourmaline structure to a maximum of 2 Li per formula unit (pfu). However, the chemical composition of our synthetic tourmaline determined by electron microprobe and secondary ion mass spectroscopy results in the formula: (X)(square Li-0.67(11)(0.33(11)))(Y)(Al2.53(10)Li0.47(10))(Z)(Al-6)T(Si5.42(15)B0.58(15))O-18(B)(BO3)(3)(V+W)[(OH)(2.40(3))O-1.60(3)], wherein a significant amount of Li occupies the X site for charge balance requirements. Reliable assignment of the OH-stretching vibrations in a polarized single-crystal Raman spectrum such as a single-crystal XRD structure refinement, confirms the incorporation of Li at the X site [0.24(9) and 0.15(5) Li-X pfu, respectively]. The SREF data show that the LiO1 distances are shortened significantly in order to compensate for the smaller ionic radius of Li+ compared to Na+, K+ or Ca2+ at the X site, i.e., Li is closer to the Si6O18 ring and to a sevenfold coordination with oxygen.},
  language  = {en}
}
@article{RibackiTrumbullLopezDeLuchietal.2022,
  author    = {Ribacki, Enrico and Trumbull, Robert B. and Lopez De Luchi, Monica Graciela and Altenberger, Uwe},
  title     = {The chemical and B-Isotope composition of Tourmaline from intra-granitic Pegmatites in the Las Chacras-Potrerillos Batholith, Argentina},
  series = {The Canadian mineralogist : journal of the Mineralogical Association of Canada},
  volume    = {60},
  journal   = {The Canadian mineralogist : journal of the Mineralogical Association of Canada},
  number    = {1},
  publisher = {Association of Canada},
  address   = {Ottawa},
  issn      = {0008-4476},
  doi       = {10.3749/canmin.2100036},
  pages     = {49 -- 66},
  year      = {2022},
  abstract  = {The Devonian Las Chacras-Potrerillos batholith comprises six nested monzonitic to granitic intrusions with metaluminous to weakly peraluminous composition and a Sr-Nd isotopic signature indicating a dominantly juvenile mantle-derived source. The chemically most evolved units in the southern batholith contain a large number of intra-granitic, pod-shaped tourmaline-bearing pegmatites. This study uses in situ chemical and boron isotopic analyses of tourmaline from nine of these pegmatites to discuss their relationship to the respective host intrusions and the implications of their B-isotope composition for the source and evolution of the magmas. The tourmalines reveal a diversity in element composition (e.g., FeO, MgO, TiO2, CaO, MnO, F) which distinguishes individual pegmatites from one another. However, all have a narrow 5 11 B range of -13.7 to -10.5\%0 (n = 100) which indicates a relatively uniform magmatic system and similar temperature conditions during tourmaline crystallization. The average delta(11) B value of -11.7\%0 is typical for S-type granites and is within the range reported for peraluminous granites. pegmatites, and metamorphic units of the Ordovician basement into which the Las Chacras-Potrerillos batholith intruded. The B-isotope evidence argues for a crustal boron source like that of the Ordovician basement, in contrast to the metaluminous to weakly peraluminous composition and juvenile initial Sr and Nd isotope ratios of the Las Chacras-Potrerillos batholith magmas. We propose that the boron was not derived from the magma source region but was incorporated from dehydration melting of elastic metasedimentary rocks higher up in the crustal column.},
  language  = {en}
}