American

Mineralogist

1995, Volume 80, July-August, number 7-8

PRESIDENTIAL ADDRESS

649 BERNARD W. EVANS, MARK S. GHIORSO Thermodynamics and petrology of cummingtonite

LETTERS

861 J. F. STEBBINS, S. SEN, I. FARNAN Silicate species exchange, viscosity, and crystallization in a low-silica melt: In situ high-temperature MAS NMR spectroscopy

865 I-MING CHOU, W. A. BASSETT, T. B. BAI Hydrothermal diamond-anvil cell study of melts: Eutectic melting of the assemblageCa(OH)2 + CaCO3 with excess H2O and lack of evidence for "portlandite II" phase

869 GEORGE D. GUTHRIE, JR., DAVID L. BISH, ROBERT C. REYNOLDS, JR. Modeling the X-ray diffraction pattern of opal-CT

ARTICLES

664 J. D. FABRIS, J.M.D. COEY, QINIAN QI, W. N. MUSSEL Characterization of Mg-rich maghemite from tuffite

670 YOUXUE ZHANG, ZHENGJIU XU Atomic radii of noble gas elements in condensed phases

676 EMIL MAKOVICKY Structural parallels between the high-pressure B phases and the leucophoenicite series

680 K. L. BARTELMEHS, R. T. DOWNS, G. V. GIBBS, M. B. BOISEN, JR., J. B. BIRCH Tetrahedral rigid-body motion in silicates

691 ANNE BOSENICK, CHARLES A. GEIGER, TORSTEN SCHALLER, ANGELIKA SEBALD 29Si MAS NMR and IR spectroscopic investigation of synthetic pyrope-grossular garnet solid solutions

705 SIMON C. KOHN, C. MICHAEL B. HENDERSON, RAY DUPREE Si-Al order in leucite revisited: New information from an analcite-derived analogue

715 HIROSHI TAKEDA, MALCOLM ROSS Mica polytypism: Identification and origin

725 D. J. YAUGHAN, K.E.R. ENGLAND, G. H. KELSALL, Q. YIN Electrochemical oxidation of chalcopyrite (CuFeS2) and the related metal-enriched derivatives Cu4Fe5S8, Cu9Fe9S16, and Cu9Fe8S16

732 GREGORY R. LUMPKIN, RODNEY C. EWING Geochemical alteration of pyrochlore group minerals: Pyrochlore subgroup Supplemental Data Available

744 JUDY BAKER, R. C. NEWTON Experimentally determined activity-composition relations for Ca-rich scapolite in the system CaAl2Si2O8-NaAISi3O8-CaCO3 at 7 kbar

752 STEVEN R. BOHLEN, JAMES 0. ECKERT, JR., W. B. HANKINS Experimentally determined solidi in the Ca-bearing granite system NaAISi3O8-CaAl2Si2O8-KAISi3O8-SiO2-H2O-CO2

757 JOHN M. EILER, JOHN W. VALLEY, COLIN M. GRAHAM, LUKAS P. BAUMGARTNER The oxygen isotope anatomy of a slowly cooled metamorphic rock

765 MICHAEL B. WOLF, DAVID LONDON Incongruent dissolution of REE- and Sr-rich apatite in peraluminous granitic liquids: Differential apatite, monazite, and xenotime solubilities during anatexis

776 BRADLEY S. SINGER, MICHAEL A. DUNGAN, GRAHAM D. LAYNE Textures and Sr, Ba, Mg, Fe, K, and Ti compositional profiles in volcanic plagioclase: Clues to the dynamics of calc-alkaline magma chambers

799 GREGORY A. SNYDER, LAWRENCE A. TAYLOR, ERIC A. JERDE ROBERT N. CLAYTON, TOSHIKO K. MAYEDA, PETER DEINES, GEORGE R. ROSSMAN, NIKOLAI V. SOBOLEV Archean mantle heterogeneity and the origin of diamondiferous eclogites, Siberia: Evidence from stable isotopes and hydroxyl in garnet

810 JODIE L. HAYOB, ERIC J. ESSENE Armalcolite in crustal paragneiss xenoliths, central Mexico

823 IAN M. STEELE Oscillatory zoning in meteoritic forsterite

833 HARTWIG E. FRIMMEL, DENNIS HOFFMANN, RON T. WATKINS, JOHN M. MOORE An Fe analogue of kinoshitalite from the Broken Hill massive sulfide deposit in the Namaqualand Metamorphic Complex, South Africa

841 YONGSHAN DAI, JEFFREY E. POST Crystal structure of hillebrandite: A natural analogue of calcium silicate hydrate (CSH) phases in Portland cement

NEW MINERAL NAMES

PRESENTATION OF AWARDS FOR 1994

851 HO-KWANG MAO Presentation of the Roebling Medal of the Mineralogical Society of America for 1994 to William A. Bassett

852 WILLIAM A. BASSETT Acceptance of the Roebling Medal of the Mineralogical Society of America for 1994

854 ALEXANDRA NAVROTSKY Presentation of the Mineralogical Society of America Award for 1994 to Ronald E. Cohen

855 RONALD E. COHEN Acceptance of the Mineralogical Society of America Award for 1994

857 GORDON E. BROWN, JR. Presentation of the Distinguished Public Service Medal for 1994 to Konrad Bates Krauskopf

859 KONRAD BATES KRAUSKOPF Acceptance of the Distinguished Public Service Medal for 1994