..., hexacelsian, and celsian. It forms transparent, light yellow to lemon-colored crystals with a white streak and a vitreous luster. They exhibit good cleavage on (001), a brittle tenacity, and a conchoidal fracture. The estimated Mohs hardness is 5. Bennesherite has a melilite-type structure with the layers...

... oxide deposit, in Värmland, Sweden, representing intermediate compositions on the walstromite–margarosanite binary, in the range ca. 50–70% mol.% BaCa 2 Si 3 O 9 . The Pb-rich walstromite is associated closely with celsian, phlogopite, andradite, vesuvianite, diopside and nasonite. A crystal-structure...

... are alstonite, baryte, celsian, diopside, fresnoite, mica, suzukiite, walstromite, witherite and minerals of the cerchiaraite group. Bavsiite is optical uniaxial (+), with ω = 1.725(3) and ε = 1.750(3) (589 nm) and pleochroic. Electron microprobe analyses yielded the empirical formula Na 0.02 Ba 1.98 Ti 0.16 Fe...

..., celsian, hyalophane, Ba-orthoclase and fresnoite, but before nepheline ± kalsilite, and later sulfates, carbonates, an unidentified ‘X-mineral’ close to Al- and Fe-rich tobermorite and goethite. Micro-Raman spectroscopy of kuratite shows five bands near 133–155 (strong), 399–401, 545–566, 684–693...

... zones. Rare thin leucocratic “aplite” dikes contain slawsonite, celsian, microcline, natrolite, prehnite, analcime, and thomsonite-Ca. Slawsonite forms aggregates exhibiting symplectite-like microstructures up to 2 mm long and is associated with euhedral zoned celsian micrograins up to 100 μm in size...

... in association with abundant celsian and hyalophane, replacing the original calcic plagioclase (bytownite). A study of this curious natural slawsonite-celsian-hyalophane assemblage provides a valuable insight into feldspar stability and petrogenesis. Whole-rock geochemical signatures of the picrite sill...

... from the Wigwam deposit of Southeastern British Columbia, Canada. It is a metamorphic mineral formed under greenschist-facies conditions as part of an assemblage that includes quartz, celsian, apatite, sphalerite, pyrrhotite, galena, pyrite, zoltaiite, and batisivite. Greenwoodite has a Mohs hardness...

...Leone Melluso; Vincenzo Morra; Roberto de’ Gennaro Abstract A Ba-rich alkali feldspar (hyalophane to almost pure celsian) coexists with melilite in the groundmass of the S. Caterina melafoidite lava, Mt. Vulture, Italy. The accompanying phases are a very Al- and Ti-rich clinopyroxene, magnetite...

.... It is closely associated with anandite, bazirite, celsian, devitoite, quartz and titantaramellite. The crystals occur in dark reddish brown foliated masses of irregular, undulating striated blades up to several mm in length, flattened on {100} and elongate and striated parallel to [001]. The mineral...

... thermal expansion coefficients for volume (α V ) have been combined with earlier results for end-member Na- and K-feldspars. Unlike AlSi 3 feldspars, Al 2 Si 2 feldspars, including anorthite and celsian from the present study, and Sr- and Pb-feldspar from other workers, show essentially constant...

...Guanghai Shi; Neng Jiang; Yuwang Wang; Xin Zhao; Xia Wang; Guowu Li; Enoch Ng; Wenyuan Cui Abstract Barium (Ba) minerals identified in clinopyroxene rocks from the Myanmar jadeitite area include celsian, hyalophane, and hydrated barium aluminum silicate (an inferred barian zeolite). The hyalophane...

...-aegirine-diopside/hedenbergite diagram extends from the jadeite-diopside/hedenbergite line toward the aegirine-rich field, maintaining approximately constant the jadeite content, resulting in an asymmetric phase diagram. Miscibility gap jadeite omphacite celsian hyalophane The composition...

...Eric J. ESSENE; Christopher L. CLAFLIN; Giovanna GIORGETTI; Pilar M. MATA; Donald R. PEACOR; Péter ÁRKAI; Mark A. RATHMELL Abstract The occurrences of natural coexisting feldspars including hyalophane and also celsian delineate two-, three- and possibly four-phase fields in the system BaAl 2 Si 2...

...Maria Candelas Moro; Maria Luisa Cembranos; Agustina Fernandez Abstract (Ba,K)-feldspars occur with cymrite as thin layers of massive fine-grained celsian interbedded with apatite, sulfides and barite, or diseminated in the thin-bedded barite-bearing siliceous and carbonate beds ranging...

...L. S. Zevin Abstract Synthetic celsian (barium feldspar) crystallized from a glass of nearly stoichiometric composition exhibited a diffraction pattem with very broad and almost absent diffraction peaks with l = odd indices (the basic ≈7.2-Å cell is assumed). Three models based on the random shift...