Vanadio-oxy-dravite, NaV3(Al4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup

Abstract Vanadio-oxy-dravite, NaV3(Al4Mg2)(Si6O18)(BO3)3(OH)3O, is a new mineral of the tourmaline supergroup. It is found in metaquartzites of the Pereval marble quarry (Sludyanka, Lake Baikal, Russia) in association with quartz, Cr-V-bearing tremolite and mica, diopside-kosmochlor-natalyite, Cr-bearing goldmanite, escolaite-karelianite, dravite-oxy-vanadium-dravite, V-bearing titanite and rutile, ilmenite, oxyvanite-berdesinskiite, shreyerite, plagioclase, scapolite, zircon, pyrite, and an unnamed oxide of V, Cr, Ti, U, and Nb. Crystals are green, transparent with a vitreous luster, pale green streak, and conchoidal fracture. Vanadio-oxy-dravite has a Mohs hardness of approximately 7½, and a calculated density of 3.14 g/cm3. In plane-polarized light, vanadio-oxy-dravite is pleochroic (O = yellow green and E = pale olive green) and uniaxial negative: ω = 1.693(5), ε = 1.673(5). Vanadio-oxy-dravite is rhombohedral, space group R3m, with the unit-cell parameters a = 16.0273(3), c = 7.2833(1) Å, V = 1620.24(5) Å3, Z = 3. Crystal-chemical analysis resulted in the empirical structural formula: X(Na0.70Ca0.23□0.05K0.02)Σ1.00Y(V3+1.39Mg1.16Al0.35Fe3+0.04Ti4+0.04Fe2+0.02)Σ3.00 Z(Al3.74Mg1.28V3+0.78Cr3+0.20)Σ6.00T(Si6.00O18) B(BO3)3V(OH)3W[O0.74(OH)0.26]Σ1.00. The crystal structure of vanadio-oxy-dravite was refined to an R1 index of 1.70% using 1800 unique reflections collected with MoKα X-radiation. Ideally, vanadio-oxy-dravite is related to oxy-dravite and oxy-vanadium-dravite by the homovalent substiution V3+ ↔ Al3+. Tourmaline with chemical compositions classified as vanadio-oxy-dravite can be either Al dominant or V dominant as a result of the compositional boundaries along the solid solution between Al and V3+ that are determined at Y+Z(V1.5Al5.5), corresponding to NaY(V1.5Al1.5)Z(Al4Mg2)Si6O18(BO3)3(OH)3O, and Y+Z(V5Al2), corresponding to NaY(V3)Z(V2Al2Mg2)Si6O18(BO3)3(OH)3O.

[1]  Martin Kuefer,et al.  Crystal Structure Analysis , 2016 .

[2]  H. Skogby,et al.  Vanadio-oxy-chromium-dravite, NaV3(Cr4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup , 2014 .

[3]  H. Skogby,et al.  Crystallographic and spectroscopic characterization of Fe-bearing chromo-aluminopovondraite and its relations with oxy-chromium-dravite and oxy-dravite , 2013 .

[4]  P. Lazor,et al.  Short-range order in tourmaline: a vibrational spectroscopic approach to elbaite , 2012, Physics and Chemistry of Minerals.

[5]  Giovanna Agrosì,et al.  Tsilaisite, NaMn3Al6(Si6O18)(BO3)3(OH)3OH, a new mineral species of the tourmaline supergroup from Grotta d’Oggi, San Pietro in Campo, island of Elba, Italy , 2012 .

[6]  B. Dutrow,et al.  Tourmaline: A Geologic DVD , 2011 .

[7]  B. Dutrow,et al.  Nomenclature of the tourmaline-supergroup minerals , 2011 .

[8]  V. Michaelis,et al.  Oscillatory zoned liddicoatite from Anjanabonoina, central Madagascar. I. Crystal chemistry and structure by SREF and 11B and 27Al MAS NMR spectroscopy , 2011 .

[9]  V. V. Hinsberg,et al.  Tourmaline: an ideal indicator of its host environment , 2011 .

[10]  Jan Filip,et al.  Compositional trends in tourmaline from intragranitic NYF pegmatites of the Třebíč pluton, Czech Republic: an electron microprobe, Mössbauer and LA–ICP–MS study , 2011 .

[11]  F. Bosi.  Stereochemical constraints in tourmaline: from a short-range to a long-range structure , 2011 .

[12]  Pavel Uher,et al.  Vanadium-bearing tourmaline in metacherts from Chvojnica, Slovak Republic: crystal chemistry and multistage evolution , 2011 .

[13]  V. V. Hinsberg,et al.  Tourmaline as a petrogenetic indicator mineral in the Haut-Allier metamorphic suite, Massif Central, France , 2011 .

[14]  B. Dutrow,et al.  The incorporation of fluorine in tourmaline: internal crystallographic controls or external environmental influences? , 2011 .

[15]  V. Michaelis,et al.  Elbaite-liddicoatite from Black Rapids glacier, Alaska , 2011 .

[16]  A. Surour,et al.  Crystal structure analyses of four tourmaline specimens from the Cleopatra’s Mines (Egypt) and Jabal Zalm (Saudi Arabia), and the role of Al in the tourmaline group , 2010 .

[17]  V. Michaelis,et al.  Mushroom elbaite from the Kat Chay mine, Momeik, near Mogok, Myanmar: I. Crystal chemistry by SREF, EMPA, MAS NMR and Mössbauer spectroscopy , 2008, Mineralogical Magazine.

[18]  F. Hatert,et al.  THE IMA–CNMNC DOMINANT-CONSTITUENT RULE REVISITED AND EXTENDED , 2008 .

[19]  G. Sheldrick.  A short history of SHELX. , 2008, Acta crystallographica. Section A, Foundations of crystallography.

[20]  G. Agrosì,et al.  Mn-tourmaline crystals from island of Elba (Italy): Growth history and growth marks , 2006 .

[21]  J. B. Selway,et al.  Schorl-oxy-schorl to dravite-oxy-dravite tourmaline from granitic pegmatites; examples from the Moldanubicum, Czech Republic , 2004 .

[22]  S. Lucchesi,et al.  Crystal chemistry of the schorl-dravite series , 2004 .

[23]  L. Reznitskii,et al.  Crystal chemistry of the dravite-chromdravite series , 2004 .

[24]  F. Hawthorne.  The use of end-member charge-arrangements in defining new mineral species and heterovalent substitutions in complex minerals , 2002 .

[25]  Stephen E. Wright,et al.  Optimization of site occupancies in minerals using quadratic programming , 2000 .

[26]  Frank C. Hawthorne,et al.  Classification of the minerals of the tourmaline group , 1999 .

[27]  E. B. Sal’nikova,et al.  U-Pb Zircon Dating of Granulite Metamorphism in the Sludyanskiy Complex, Eastern Siberia , 1998 .

[28]  A. Lebedev,et al.  Optical absorption spectroscopy of synthetic tourmalines , 1993 .

[29]  J. Grice,et al.  Ordering of Fe and Mg in the tourmaline crystal structure: The correct formula Sample: Dravite 43873 , 1993 .

[30]  J.-L. Pouchou,et al.  Quantitative Analysis of Homogeneous or Stratified Microvolumes Applying the Model “PAP” , 1991 .

[31]  Franklin F. Foit.  Crystal chemistry of alkali-deficient schorl and tourmaline structural relationships , 1989 .

[32]  J. Sanz,et al.  Infrared and electron microprobe analysis of tourmalines , 1988 .

[33]  G. Rossman,et al.  Fe2+-Fe3+ interactions in tourmaline , 1987 .

[34]  I. D. Brown,et al.  Bond‐valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure Database , 1985 .

[35]  Gordon Smith.  A reassessment of the role of iron in the 5,000–30,000 cm−1 region of the electronic absorption spectra of tourmaline , 1978 .

[36]  J. A. Mandarino.  The Gladstone-Dale relationship; Part I, Derivation of new constants , 1976 .