 | | Journal (article/letter/editorial) | | Sciences, University of Washington, Seattle, WA 98195, USA Abstract. Electron diffraction and electron microscopic...is comparable to the ~ - / 3 phase transition in quartz. Introduction The crystal structure of anorthite...CaA12Si20 s at room temperature was determined by Kempster et al. (1962) and refined by Wainwright and Starkey...occurs in cm size crystals in association with quartz and chlorite in a low temperature metamorphic rock...observations made during the -13 transition in quartz including the formation of the incommensurate phase |  | | Journal (article/letter/editorial) | | Department of Geology, University of Wisconsin, Madison 6, Wisconsin, U . S . A . (Received 6 June 1962...with isolated tetrahedra. At the University of Wisconsin, S. W. Bailey was finding t h a t the Si, A1-O...the same Si : A1 ratio. At the same time, Megaw, Kempster & Radoslovich (1962) were finding that the Si-O...746 1.7h6 1.752 1.752 1.753 1.758 1.681 Hegaw, Kempster and Radosiov[ch (19621 0.003 1.622 1.622 Fischer...times 0.006 1.639 1.639 Gibbs and Smith 41962) quartz (low) Si 02 1.603 twice 1.611 twice 0.003 |  | | Journal (article/letter/editorial) | | indexing, we prepared a thin sample deposited on a quartz monocrystal, (zero-background sample holder, obtained...of 933 A 3 suggested, following the Kempster-Lipson rule (Kempster and Lipson, 1972), a cell content of...analysis," J. Appl. Crystallogr. 21, 228-239. Kempster, C. J. E., and Lipson, H. (1972). "A rapid method |  | | Journal (article/letter/editorial) | | A 3 Ê thumb' of `18 A per non-hydrogen atom' (Kempster & Lipson, 1972), it was concluded that the unit...onto a ¯at-plate sample holder consisting of a quartz so as to obtain low single crystal cut 4 away...been repeated in transmission mode using a 0.7 mm quartz capillary at beamline BM16 of the European Synchrotron...(ICDD), 1601 Park Lane, Swarthmore, PA 19081-2389, USA. The following are available as supplementary data:...mode Ê ); strong preferred orientation. (b) 0.7 mm quartz ( 1.15 A Ê ); no texture effects. capillary |  | | Journal (article/letter/editorial) | | ~ ¼ and c ~ ¾ are no longer equivalent (e.g., Kempster et al. 1962; Wenk and Kroll 1984). Cell parameters...Their sample was a natural low albite from Amelia County, Virginia, with Al almost exclusively occupying...compared to 0.02–0.89 for olivine, 0–1.86 km/s for quartz, 0.02–1.87 km/s for hornblende, 0.09–1.69 km/s...common crustal minerals, e.g., olivine = 0.22, quartz = 0.28, hornblende = 0.33, gypsum = 0.36, biotite...transformations in silica. Physical Review B, 55, 3465. Kempster, C.J.E., Megaw, H.D., and Radoslovich, E.W. (1962) |  | Dostal, Jaroslav, Keppie, Duncan J., Jutras, Pierre, Miller, Brent V., Murphy, Brendan J. (2006) Evidence for the granulite–granite connection: Penecontemporaneous high-grade metamorphism, granitic magmatism and core complex development in the Liscomb Complex, Nova Scotia, Canada. Lithos, 86 (1) 77-90 doi:10.1016/j.lithos.2005.04.002 | Journal (article/letter/editorial) | | A&M University, College Station, Texas 77843-3115, USA d Department of Earth Sciences, St. Francis Xavier...The insert displays eastern Canada, northeastern USA, and the location of the map. It also shows the lithotectonic...non-migmatitic rocks ranging from augen gneiss (quartz–K-feldspar–plagioclase– biotite–muscovite–sillimanite)...gneiss (quartz–K-feldspar–plagioclase–hornblende–biotite) to quartzo–feldspathic gneiss (quartz– K-fel...e–sillimanite– garnet) and sillimanite schist (quartz–plagioclase–cordierite–biotite–sillimanite) (Clarke |  | Pautov, L. A., Agakhanov, A. A., Sokolova, E., Hawthorne, F. C. (2004) Maleevite, BaB2Si2O8 and pekovite, SrB2Si2O8, new mineral species from the Dara-i-Pioz alkaline massif, Northern Tajikistan: description and crystal structure. The Canadian Mineralogist, 42 (1) 107-119 doi:10.2113/gscanmin.42.1.107 | Journal (article/letter/editorial) | | luster. Maleevite occurs in aegirine – microcline – quartz pegmatite in syenites with arfvedsonite, polylithionite...Pekovite occurs in a rock consisting mainly of quartz with subordinate pectolite, aegirine, stillwellite-(Ce)...Pekovite commonly forms intergrowths with pectolite, quartz, strontian fluorite and aegirine. Maleevite fluoresces...un bloc de pegmatite à aegyrine – microcline – quartz dans une syénite, est associée à arfvedsonite,...pékovite se présente dans une roche faite surtout de quartz, avec pectolite, aegyrine, stillwellite-(Ce), polylithionite |  | | Journal (article/letter/editorial) | | which Ca cations occupy large interstitial sites (Kempster et al. 1962). Brown et al. (1963) ®rst discovered...atoms (Ca(000), Ca(z00), Ca(0i0), and Ca(zi0)) (Kempster et al. 1962). By the transition to the I 1 structure...MXDTRICL. Japan Chemistry Program Exchange, 077 Kempster CJE, Megaw HD, Radoslovich EW (1962) The structure...Symmetry and its change in a reciprocal space of a quartz crystal simulated by molecular dynamics. Acta Crystallogr |  | | Journal (article/letter/editorial) | | Tangier anticline, which contains abundant auriferous quartz veins formed during flexural-slip folding during...regional-scale anticlines. The veins are dominated by quartz, Ca-Mg-Fe carbonates, and Fe sulfides, may contain...rocks and gabbroic bodies (e.g., Liscomb area) Kempster et al. (1989) Kontak and Reynolds (1994) Gold...slates. Both bedding-concordant and -discordant quartz veins occur; concordant veins lie preferentially...laminated quartz (i.e., ribbon or crack-seal texture; stage 1) are separated by massive white quartz (stage |  | | Journal (article/letter/editorial) | | (Bragg and Brown 1926b). The crystal structure of quartz and its high-temperature polymorphs showed that...(Angel et al. 1990) or several months in the 1950s (Kempster et al. 1962)! A data collection to 2qmax = 100°...tetrahedron (closed symbols with error bars). Data from Kempster et al. (1962), Wainwright and Starkey (1971),...minerals such as sanidine (Taylor 1933) or anorthite (Kempster et al. 1962) represented a significant contribution...Proceedings of the National Academy of Sciences of the USA, 11, 489–493. Farrugia, L. (2014) Accurate H-atom |  | | Journal (article/letter/editorial) | | Illinois at Urbana-Champaign, Urbana, IL 61801, USA Received September 23, 1994/Revised, accepted January...University of California at Davis, Davis, CA 95616, USA Correspondence to: B.L. Phillips especially relevant...four tetrahedral A1 neighbors and vice versa (Kempster et al. 1962; Wainwright and Starkey 1971 ; Angel...spin-lattice relaxation across the e-/? transition in quartz, whereas a significant increase of the relaxation...body-centered phase at 514 K. Z Kristallogr 204: 21~237 Kempster CJE, Megaw HD, Radoslovich EW (1962) The structure |  | | Journal (article/letter/editorial) | | groups of xenoliths occur. Both groups contain quartz + feldspar + biotite + Fe - Ti oxides + sulfides...1990). These dykes, emplaced at around 370 Ma (Kempster et al. 1989), are a potentially important part...groundmass of plagioclase, hornblende, biotite, quartz, and calcite, with accessory opaques and apatite...white mica. Relict minerals in the dyke include quartz, feldspars, clinopyroxene, altered orthopyroxene... Other minerals possible in this group include quartz, subsilicic orthopyroxene, mesoperthite, plagioclase |  | | Journal (article/letter/editorial) | | C. J . E. KEMPSTER, HELEN I). MEGAW large ~ t h e y d i v e r g e d a t small ~. H e n c e e m p i...H. D. (1956). Acta Cryst. 9, 56. MEGAW, H. D., KEMPSTER, C. J. E. & I:~ADOSLOVICH, E. W. (1962). Acta...Description and Discussion B Y HELEN D. MEGAW, C. J. E. KEMPSTER* AND E. W. I~ADOSLOVICHt Crystallographic Laboratory...Si/A1 arrangement, have already been reported (Kempster, M e g a w & R a d o s l o v i c h , 1960). Ca(z0c)...should be shorter t h a n in a structure such as quartz where none of the O's has a n y other neighbour |  | | Journal (article/letter/editorial) | | Ma; Reynolds et al., 1987; Muecke et al. 1988). Kempster et al. (1989) presented 40Ar/39Ar plateau dates...are shoshonitic lamprophyres (Owen et al., 1988; Kempster et al., 1989). Xenocrysts and xenoliths infiveof...suggesting that they may have been phenocrysts. Quartz (<5 vol.%) is a significant, interstitial, fine-grained...%) phases. Calcite is generally associated with quartz but also forms oval globules ^0-8 mm long in sample...rocks (b). Minette—average of three North Carolina (USA) minettes reported by Mauger (1988). Spessartite—average |  | | Journal (article/letter/editorial) | | effects assorciatedwith the Dauphin6 twins in o quartz and the c-antiphase domains(c-APDs) in Pl anor...6 kJ/mol. In contrast to the Dauphin6 twins of quartz, the c-APDs of anorthite did not appearto interact...manganoanpigeonite(Gordon et al. 1981; Carpenter1994)' quartz (Frondel 1945; Young 1962:' Inoue et al. 1974;'...1990). However, the recovery of Dauphin6 twins in quartz and of c-antiphasedomains (c-APDs) in anorthite...Differences in the memory behavior exhibited by quartz and anorrhite suggestsubtle differencesin the causesof |  | | Journal (article/letter/editorial) | | The room temperature structure of anorthite (Kempster et al. 1962) comprises a flexible framework of...rotating anode Cu X-ray source was used with a bent quartz monochromator selecting K c~1radiation. After a...m6glicher Alternativen. Dissertation. Univ M/inchen Kempster CJE, Megaw HD, Radoslovich EW (1962) The structure |  | | Journal (article/letter/editorial) | | group P1. The crystal structure was determined by Kempster et al. (1962) and refined by Czank (1973) and...Huber 632 heating Guinier powder camera. A bent quartz monochromator selected CuKcq radiation and reduced...1:227~31 Kalus C (1978) Dissertation. Univ. Miinchen Kempster CJE, Megaw HD, Radoslovich EW (1962) The structure |  | | Journal (article/letter/editorial) | | radionuclides in South African water resources (Kempster et al., 1996). Elevated uranium and radium concentrations...dark coloured organicrich materials, rather than quartz-rich tailings type materials. 497 2. In a number...Forestry., South Africa, Report, N/C200/00//RPQ/2399. Kempster, P L, van Vliet, H R, Looser, U, Parker, I, Silberbauer |  | | Journal (article/letter/editorial) | | disorder because Al atoms alternate with Si atoms (Kempster et al., 1962; Megaw et aL., 1962).From factor-group...tectosilicates Mineralg 1. 2. 3. 4. 5. 6. 7. a-qErtz B-quartz (700'C) a-crlstobalite Coeslte LlA1S1206-Irr LlA1S1206...SHARMA ET AL.: ANORTHITE. PYROXENE,AND GEHLENITE Kempster et al. (1962)and Megaw et al. (1962)have examined...Jahrbuch ftir Mineralogie, Abhandlungen,I 15,98-l 19. Kempster, C. J. E., Megaw, H. D. and Radoslovich,E. W....CosmochimicaActa, 46,2021-2037. Megaw, H. D., Kempster, C. J. E. and Radoslovich,E. W. (1962)The structure |  | | Journal (article/letter/editorial) | | respectively. The natural An100 grains are associated with quartz and chlorite. The An92Ab8 sample consists of homogeneous...sites: Ca(000), Ca(0i0), Ca(z00), and Ca(zi0) (Kempster et al. 1962), where i and z denote translations...Zeitschrift für Kristallographie, 204, 215–237. Kempster, C.J.E., Megaw, H.D., and Radoslovich, E.W. (1962) |  | | Journal (article/letter/editorial) | | Harbour dyke are enclosed by feldspathic ( _+rare quartz ) haloes that embay aluminosilicates and biotite...presence of quartz at relatively low temperatures (e.g., Montel et al., 1986). Stable sapphirine-quartz and spinel-quartz...spinel-quartz assemblages in metapelites are estimated to have formed at pressures and temperatures in... 1000-1400°C) have been inferred, however, for quartz-free, sapphirine- and pyroxene-bearing rocks of...part of a swarm of northwest-trending, Devonian (Kempster et al., 1989) mafic intrusions on the eastern |  | | Journal (article/letter/editorial) | | Saskatoon, Saskatchewan, CanadaS7NOWO Abstract Vein quartz,carbonate, andtourmaline from 19 Megumagolddeposits...with low-temperature fluidsbasedon analyses of quartz-carbonate pairsthat indicatedisc uilibriumfraetionation(A...Clarkeet al., 1993b)andminorgabbroie material(Kempster Thedeposits canbebroadly grouped depending onwhether...KERRICH TABLE 1. Isotopic DataforVeinCarbonate, Quartz,andTourmaline, Meguma GoldDeposits, NovaScotia...sampleno. •5•80 8•SO carbonate carbonate 87Sr/'S6Sr quartz carbonate (%0) (%0) (%0) MR-86-19.2 MR-87-1 MR-86-102 |  | | Journal (article/letter/editorial) | | reedmergneriteand temperaturesfor its incongruentmelting to quartz and glasshave beendescribedby Eugster and \IcIver... dry, occursat 831o-l-40 C. r'viththe products quartz, glassand tridymite. No changewas observedin the...Low Ar-r:rTE, NaAr,Sr:Os Reedmergnerite Duchesne County, Utah Present study Direct-cell MrNnnars Low...(1964), and the extensive studies of anorthite by Kempster, et al. (1962) and Megaw et al. (1962). A review...averageisotropic temperature factors in anorthite (Kempster el al., 1962) and in maximum microcline (Brown |  | Rukiah, Mwaffak, Lefebvre, Jacques, Descamps, Marc, Hemon, Stephanie, Dzyabchenko, Alexander (2004) Abinitiostructure determination ofm-toluidine by powder X-ray diffraction. Journal of Applied Crystallography, 37 (3). 464-471 doi:10.1107/s0021889804006478 | Journal (article/letter/editorial) | | INEL sensitive curved detector, CPS120. A bent quartz monochromator enables the selection of the K 1...molecules per unit cell is also in agreement with the Kempster Ê 3 per non-H & Lipson (1972) `rule of thumb'...Tremayne M. (1996). Chem. Mater. 8, 2554±2570. Kempster, C. J. E. & Lipson, H. (1972). Acta Cryst. B28 |  | | Journal (article/letter/editorial) | | oxygen anions coordinated by three (1.625A). Megaw, Kempster and Radoslovich(1962), Slaughter (1966) and McDonald...CoonorNerronNulmrn Silicate Si-O" C N.b low quartz low quartz 1ow quartz low cristobalite coesite narsarsukite...Si{- distances.In anorthite C-ri:S.O and in low quartz C.N:2.0; this partly explainswhy the Si-O (1.614A)...slightly longer than the Si-O (1.607 A; in lo* quartz (Young and Post, 1962). On the other hand, the...1954). For example,the data tabulated below for low quartz (Young and Post, t962), zircon (Robinson and Gibbs |
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