American Mineralogist, 2006, V 91, N 5-6, May-June.

LETTERS
 
953
The oxidation state of vanadium in 
titanomagnetite from layered basic intrusions 
Etienne Balan, Johan P.R. De Villiers, 
Sigrid Griet Eeckhout, Pieter Glatzel, 
Michael J. Toplis, Emmanuel Fritsch, 
Thierry Allard, Laurence Galoisy, 
and Georges Calas 

957
Observation of bicarbonate in calcite 
by NMR spectroscopy 
Jian Feng, Young J. Lee, Richard J. Reeder, 
and Brian L. Phillips 

961
Single-crystal elastic properties of
dense hydrous magnesium silicate phase A 
Carmen Sanchez-Valle, Stanislav V. Sinogeikin, 
Joseph R. Smyth, and Jay D. Bass 

ARTICLES
 
717
Hourglass sector zoning in metamorphic tourmaline
and resultant major and trace element fractionation 
Vincent J. van Hinsberg, John C. Schumacher, 
Stuart Kearns, Paul R.D. Mason, and Gerhard Franz 

729
Occurrence and late re-equilibration of 
pollucite from the Koktokay no. 3 pegmatite, 
Altai, northwestern China 
Ru Cheng Wang, Huan Hu, Ai Cheng Zhang, 
Francois Fontan, Hui Zhang, 
and Philippe de Parseval 

740
the Al2SiO5 polymorphs, andalusite, 
sillimanite, and kyanite: X-ray 
photoelectron- and electron energy 
loss spectroscopy studies 
Fumio S. Ohuchi, Subrata Ghose, 
Mark H. Engelhard, and Donald R. Baer 

747
Application of the simple salt lattice 
energy approximation to the solubility of minerals 
Claude H. Yoder and Jeffrey P. Rowand 

753
Quench rate and temperature effects on 
framework ordering in aluminosilicate melts 
Emily V. Dubinsky and Jonathan F. Stebbins 

762
The effect of sodium on the solubilities 
of metals in silicate melts 
Alexander Borisov, Yann Lahaye, and Herbert Palme 

772
Nanotunnels and pull-aparts: Defects of 
exsolution lamellae in alkali feldspars 
John D. Fitz Gerald, Ian Parsons, 
and Nicola Cayzer 

784
The structure and distribution of carbon 
in 3.5 Ga Apex chert: Implications for the 
biogenicity of Earth's oldest putative 
microfossils 
Bradley T. De Gregorio and Thomas G. Sharp 

790
Site disorder revealed through Raman 
spectra from oriented single crystals: 
A case study on karooite (MgTi2O5) 
Hanns-Peter Liermann, Robert T. Downs, 
and Hexiong Yang 

794
Single-crystal diffraction and transmission 
electron microscopy studies of "silicified" 
pyrochlore from Narss?rssuk, Julianehaab 
district, Greenland 
Paola Bonazzi, Luca Bindi, Matteo Zoppi, 
Gian Carlo Capitani, and Filippo Olmi 

802
Compressibility of synthetic potassium-rich 
clinopyroxene: In-situ high-pressure 
single-crystal X-ray study 
Luca Bindi, Robert T. Downs, 
George E. Harlow, Oleg G. Safonov, 
Yuriy A. Litvin, Leonid L. Perchuk, 
Hinako Uchida, and Silvio Menchetti 

809
The effect of Ca substitution on the 
elastic and structural behavior of 
orthoenstatite 
Fabrizio Nestola, G. Diego Gatta, 
and Tiziana Boffa Ballaran 
 
816
Dehydroxylation, proton migration, 
and structural changes in heated talc: 
An infrared spectroscopic study 
Ming Zhang, Qun Hui, Xiao-Jie Lou,
Simon A.T. Redfern, Ekhard K.H. Salje, 
and Serena C. Tarantino 

826
Stabilizing of methane hydrate and 
transition to a new high-pressure
structure at 40 GPa 
Hisako Hirai, Shin-ichi Machida, 
Taro Kawamura, Yoshitaka Yamamoto, 
and Takehiko Yagi 

831
Upper limit of the tetrahedral rotation 
angle and factors affecting octahedral 
flattening in synthetic and natural 
1M polytype C2/m space group micas 
Patrick H.J. Mercier, Denis G. Rancourt, 
Guenther J. Redhammer, Andre E. Lalonde,
Jean-Louis Robert, Rob G. Berman, 
and Hideomi Kodama 

850
Cation order and hydrogen bonding of 
high-pressure phases in the 
Al2O3-SiO2-H2O system: An NMR and Raman study 
Xianyu Xue, Masami Kanzaki, 
Hiroshi Fukui, Eiji Ito, and Takafumi Hashimoto 

862
Relationship among metamorphic grade, 
vesuvianite "rod polytypism," 
and vesuvianite composition 
Edwin Gnos and Thomas Armbruster 

871
Assignment of infrared OH-stretching 
bands in calcic amphiboles through 
deuteration and heat treatment 
Kiyotaka Ishida and Frank C. Hawthorne 

880
Direct determination of cation site 
occupancies in natural ferrite 
spinels by L2,3 X-ray absorption 
spectroscopy and X-ray magnetic 
circular dichroism 
Carolyn I. Pearce, C. Michael B. Henderson, 
Richard A.D. Pattrick, 
Gerrit van der Laan, and David J. Vaughan 

894
Heat capacities and entropies of 
mixing of pyrope-grossular 
(Mg3Al2Si3O12-Ca3Al2Si3O12) garnet 
solid solutions: A low-temperature 
calorimetric and a thermodynamic 
investigation 
Edgar Dachs and Charles A. Geiger 

907
Fe2+ and Fe3+ quantification by different 
approaches and ?O2 estimation for 
Albanian Cr-spinels 
Marco Quintiliani, Giovanni B. Andreozzi, 
and Giorgio Graziani 

917
Inversion twinning in troilite 
Roman Skala, Ivana Cisacova, 
and Milan Drabek 

922
Chivruaiite, Ca4(Ti,Nb)5[(Si6O17)2|(OH,O)5]·13-14H2O, 
a new mineral from hydrothermal veins of 
Khibiny and Lovozero alkaline massifs 
Yuri P. Men'shikov, Sergey V. Krivovichev, 
Yakov A. Pakhomovsky, Victor N. Yakovenchuk, 
Gregory Yu. Ivanyuk, Julia A. Mikhailova, 
Thomas Armbruster, and Ekaterina A. Selivanova 

929
Pseudojohannite from Jachymov, Musonoi, 
and La Creusaz: A new member of the zippeite-group 
Joel Brugger, Kia Sheree Wallwork, 
Nicolas Meisser, Allan Pring, Petr Ondrus, 
and Jiry Cejka 

937
Scheuchzerite, Na(Mn,Mg)9[VSi9O28(OH)](OH)3, 
a new single-chain silicate 
Joel Brugger, Sergey Krivovichev, 
Nicolas Meisser, Stefan Ansermet, 
and Thomas Armbruster 

944
Mn-tourmaline crystals from island of Elba (Italy):
Growth history and growth marks 
Giovanna Agrosi, Ferdinando Bosi, 
Sergio Lucchesi, Giovanni Melchiorre, 
and Eugenio Scandale 

PRESENTATION OF AWARDS FOR 2005 
  
965
Presentation of the Roebling Medal for 2005 
of the Mineralogical Society of America to Ho-kwang Mao 
Charles T. Prewitt 

967
Acceptance of the Mineralogical Society 
of America Roebling Medal for 2005 
Ho-kwang "David" Mao 

969
Presentation of the Mineralogical Society 
of America Award for 2005 to Tiziana Boffa Ballaran 
Ross J. Angel 

971
Acceptance of the Mineralogical Society of 
America Award for 2005 
Tiziana Boffa Ballaran 

973
Presentation of the Distinguished 
Public Service Medal of the Mineralogical 
Society of America for 2005 to Robin Brett 
Peter J. Wyllie 

975
Acceptance of the Distinguished 
Public Service Medal for 2005 
Robin Brett 

976
Presentation of the Mineralogical Society 
of America Dana Medal for 2005 
to William D. Carlson 
W.G. Ernst 

977
Acceptance of the Dana Medal of the 
Mineralogical Society of America for 2005 
William D. Carlson