... (NaAlSi 3 O 8 ) = jadeite (NaAlSi 2 O 6 ) + quartz (SiO 2 ) reaction at 800 and 1000 °C ( Holland 1980 ) using BaCO 3 cells. Third, we investigated the anorthite (CaAl 2 Si 2 O 8 ) + gehlenite (Ca 2 Al 2 SiO 7 ) + corundum (Al 2 O 3 ) = kushiroite (3CaAl 2 SiO 6 ) reaction ( Hays 1966a , 1966b...

...William L. Griffin; Sarah E.M. Gain; Martin J. Saunders; Jin-Xiang Huang; Olivier Alard; Vered Toledo; Suzanne Y. O'Reilly Abstract Xenolithic corundum aggregates in Cretaceous mafic pyroclastics from Mount Carmel contain pockets of silicate melts with mineral assemblages [SiC (moissanite), TiC, Ti...

... by detailed petrography, Raman spectroscopy, microthermometry, and in situ titanite laser ablation-inductively coupled plasma-mass spectrometry dating. Some fluid inclusions in the corundum show an interesting morphology with a diaspore crystal fully separating the whole inclusion into two smaller inclusions...

... , constitute four inclusions up to 50 μm across in corundum recovered from the Cr-11 podiform chromitite orebody near Kangjinla, Luobusa ophiolite, Tibet, China. EELS, EDS, and 3D electron diffraction were applied to study the phases. In one inclusion, jingsuiite forms a rounded grain 40 μm across. Associated...

... stages of their evolution, recording a continuous decrease in oxygen fugacity ( f O 2 ) as crystallization proceeded. Corundum coexisting with Fe-Mg-Cr-Al spinels, other Fe-Mg-Al-Na oxides, and Fe-Ni alloys in apparent cumulates crystallized at f O 2 values near the iron-wüstite (IW) buffer ( f O 2 = IW...

...Xi-Sheng Xu; Xiao-Ming Chen; William L. Griffin; Suzanne Y. O'Reilly; Xi-Song Zhang; Li-Hui Chen Abstract Controversies on the origin of zircon, corundum, titanomagnetite, and quartz megacrysts in alkali basalts mostly reflect the lack of direct evidence of a “melt reservoir” required...

... of diamond and deltalumite from Koryaksky volcano; coexistence with super-reduced corundum and moissanite, Mn-Ni silicide inclusions, F-Cl enrichment and F/Cl ratios, and carbon and nitrogen isotopes in Tolbachik diamonds, as well as microtwinning, Mn-Ni silicides, and other inclusions in microcrystalline...

... basalt, gabbro, noritic orthopyroxenite, orthopyroxenite, dunite, harzburgite, and dacite. No other lithology has been reported up to date. In this study, we report a new occurrence of corundum in eucrite meteorite Northwest Africa (NWA) 8647. Three-dimensional petrographic observations reveal...

...William L. Griffin; Sarah E.M. Gain; Martin Saunders; Luca Bindi; Olivier Alard; Vered Toledo; Suzanne Y. O'Reilly Abstract Titanium diboride (TiB 2 ) is a minor but common phase in melt pockets trapped in the corundum aggregates that occur as xenoliths in Cretaceous basaltic volcanoes on Mt...

...Shreya Karmakar; Subham Mukherjee; Upama Dutta Abstract Growth of corundum in metamorphosed anorthosites and related basic-ultra-basic rocks is an exceptional feature, and its origin remains elusive. We describe the occurrence of and offer an explanation for the genesis of corundum in anorthositic...

... evolution mineral ecology natural kinds vapor deposition condensation astromineralogy stardust diamond graphite corundum moissanite hibonite amorphous phases “ The science of Mineralogy has made rapid progress in the past six years; chemistry has opened to us a better knowledge...

..., ilmenite, and apatite lamellae in garnet from the Brimfield Schist, Connecticut (≥1000 °C metamorphism; Central Maine Terrane, U.S.A.). We analyzed these data alongside published EBSD data for rutile, ilmenite, and corundum from metapegmatites metamorphosed in the eclogite facies from the Austrian Alps...

...Barbara L. Dutrow; Darrell J. Henry; Ziyin Sun Infiltration of out-of-equilibrium fluids can lead to extensive fluid–rock interactions resulting in unusual and uncommon mineral assemblages that are petrologically and mineralogically important. The corundum (cor)–tourmaline (tur)–phlogopite rocks...

...J. Victor Owen; Jacob J. Hanley; Mitchell J. Kerr; Matthew Stimson; Brandon Boucher Abstract Frenchvale quarry, once mined for dolomitic marble, contains pink corundum-bearing, quartz-free/-poor, feldspathic gneiss that is unusually sodic (~7% wt.% Na 2 O) and iron-poor (~0.6 wt.% Fe 2 O 3...

... of hopper/skeletal Ti-rich corundum, which have trapped melts that crystallized at f O 2 extending from 7 log units below the iron-wustite buffer (ΔIW = –7; SiC, Ti 2 O 3 , Fe-Ti silicide melts) to ΔIW ≤ –9 (native V, TiC, and TiN). The assemblage hibonite + grossite + spinel + TiN first crystallized late...

...Victor V. Sharygin Abstract The intergrowths of Fe-rich corundum + Al-rich hematite + spinel + hibonite have been found as an assemblage in a plagioclase-clinopyroxene rock (paralava, former hornfels) at the Hatrurim Basin, Hatrurim combustion metamorphic Formation. Most spinels show oriented...

... underutilized potential for pinpointing peak metamorphic conditions, particularly pressure, because of their resilience to melting and the variety of refractory minerals they contain. The typical silica-undersaturated mineral assemblage is garnet + spinel + corundum + plagioclase + K-feldspar + biotite...

...Dmitry P. Krylov; Robert A. Evarestov Equilibrium oxygen isotope ( 18 O/ 16 O) fractionations ( β -factors) for corundum are predicted from first principles using the “frozen phonon” technique within the density functional theory (DFT). Calculations of the phonon frequencies and the isotopic...

..., and oxygen isotope ratios in blue to reddish-violet sapphires from Yogo Gulch, Montana, U.S.A., with rubies from the Chantaburi-Trat region of Thailand and the Pailin region of Cambodia. The similarities between Thai/Cambodian rubies and Yogo sapphires suggest a common origin for gem corundum from both...

... ) Heat treating the sapphires of Rock Creek, Montana . Gems & Gemology , 29/4 , 250 – 272 . Guo , J. , O'Reilly , S.Y. , and Griffin , W.L. ( 1996 ) Corundum from basaltic terrains: a mineral inclusion approach to the enigma . Contributions to Mineralogy and Petrology , 122...