...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...

... of America 2020 Mineralogical Society of America Classification mineral 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...

...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...

..., 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...

...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...

...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...

... 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...

..., 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...

... needles with shape-preferred orientation included in gem corundum result from epitaxy of rutile on the corundum surface during growth of corundum in a magmatic environment. This is in contrast to the presently accepted view of oriented rutile needles in corundum being products of exsolution during cooling...

...Aaron C. Palke; Christopher M. Breeding The authors thank Associate Editor Fabrizio Nestola and Managing Editor R. Russell for their careful handling of this manuscript. References Cited Altherr , R. , Okrusch , M. , and Bank , H. ( 1982 ) Corundum- and kyanite...

...Jacqueline Wong; Charles Verdel; Charlotte M. Allen Abstract Significant uncertainty surrounds the processes involved in the formation of basalt-hosted corundum, particularly the role that the mantle plays in corundum generation. Some previous studies have suggested that trace-element ratios...

... materials in the ophiolites, are still enigmatic. Studies of a recently recognized SuR mineral system from Cretaceous volcanics on Mt Carmel, Israel, suggest an alternative genesis for the ophiolitic SuR phases. The Mt Carmel SuR mineral system (associated with Ti-rich corundum xenocrysts) appears...

..., are considered to be prospective for sapphire (corundum), lapis lazuli (lazurite), and spinel gem deposits. This research is an investigation of the hyperspectral signature of rocks from the Beluga sapphire occurrence near Kimmirut, Nunavut. Thirty-five rock and thin section offcut samples from the Beluga...

...Philippe M. Belley; Tashia J. Dzikowski; Andrew Fagan; Jan CempÍrek; Lee A. Groat; James K. Mortensen; Mostafa Fayek; Gaston Giuliani; Anthony E. Fallick; Paul Gertzbein Abstract Gem-quality corundum (sapphire) occurs in scapolite-rich calc-silicate rock hosted in marble of the Lake Harbour Group...

...-ultramafic hosted ruby deposits worldwide; (2) distinctive geochemical fingerprints for Paranesti; and (3) the likely P - T conditions of formation. Detailed petrographic and whole-rock analyses utilizing ICP-MS, XRF, and XRD have found the Paranesti corundum to be of a mafic/ultramafic protolith...

...Aaron C. Palke; Christopher M. Breeding Abstract Trace-element chemistry and microscopic observations of included gem corundum (α-Al 2 O 3 ) suggests a new model of syngenetic growth of oriented rutile inclusions rather than the usual interpretation of their growth through exsolution. Laser...

...Fahui Xiong; Jingsui Yang; Yildirim Dilek; Xiangzhen Xu; Zhongming Zhang Abstract We have recovered unusual mineral assemblages of diamond, moissanite, zircon, quartz, corundum, rutile, titanite, almandine garnet, kyanite, and andalusite from the peridotites of the Late Triassic Dingqing ophiolite...

... magnetite and corundum were the most important. Mössbauer spectroscopy revealed that the initial hercynite was a normal spinel with a slight inversion degree of 11 %, which was increased to 34 % after the 36-h annealing process. An overlapping of reflections for spinel-like phases γFe 2 O 3 and γAl 2 O 3...