Abstract

Crystals of Ga-rich, Fe-bearing tourmaline (∼25 wt% Ga2O3, 11 wt% FeOtotal) were grown from hydrothermal solution at 100 MPa and 600°C. The crystals were grown on a seed as a newly formed, up to 200 μm thick layer and, in addition, as free, spontaneously nucleated elongated prisms, 10 to 200 μm in size. The crystal structure of the synthetic tourmaline was studied by Mossbauer spectroscopy and single-crystal X-ray diffraction (to an R -index of 0.032; a = 16.000 (1), c = 7.257(1) A). Gallium and iron cations are distributed over the Y and Z octahedral sites according to the crystal-chemical formula (Na0.95□0.05) (Ga1.34Fe2+ 0.62Al0.44Fe3+ 0.34Ni0.26) (Al3.28Ga1.92 Fe2+ 0.41Fe3+0.39) (Si6O18) (BO3)3 (OH2.29O0.71) (O), suggesting that the disordered distribution previously shown for Al3+ also holds for other trivalent cations in tourmalines.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.