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trigonal paragonite

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Journal Article
Published: 01 December 1956
American Mineralogist (1956) 41 (11-12): 940–942.
...Richard V. Dietrich Abstract Trigonal paragonite, which, to the writer's knowledge, has never been reported to occur at any locality, has been found to occur with kyanite at two localities on the western part of the Piedmont of Virginia. The identity of the mica from these localities was determined...
Journal Article
Published: 01 April 2013
American Mineralogist (2013) 98 (4): 651–664.
... shells through which seismic waves pass. Computational methods can yield an additional, detailed, free-of-heterogeneity model knowledge of the mineral series of interest. Therefore, a computational study on the influence of the interlayer cation in the muscovite-paragonite (Ms-Pg) series on the crystal...
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Journal Article
Published: 01 August 2007
American Mineralogist (2007) 92 (8-9): 1531–1534.
... facing tetrahedral six-member rings accommodate three (Fe 3+ ,Mg) cations and one third of the spaces are completely vacant. The (Fe 3+ ,Mg) cations are coordinated by six or five oxygen atoms forming trigonal prisms or square pyramids, respectively. Crystal structure electron microscopy electron...
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Journal Article
Published: 01 December 2011
Mineralogical Magazine (2011) 75 (6): 2847–2855.
..., Sicily, Italy. Cossaite is trigonal, space group R 3İ, with a = 22.010(2), c = 9.238(1) Å, V = 3875.6(6) Å 3 , Z = 3. It forms stout prismatic hexagonal crystals up to 100 μm in size, terminated by rhombohedral faces, and is associated with thermessaite, vlodavetsite, sassolite and salammoniac. Cossaite...
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Journal Article
Published: 01 September 2000
European Journal of Mineralogy (2000) 12 (5): 955–963.
...Joseph R. SMYTH; Steven D. JACOBSEN; R. Jeffrey SWOPE; Ross J. ANGEL; Thilo ARLT; Kenneth DOMANIK; John R. HOLLOWAY Abstract The crystal structures of co-existing monoclinic 2 M 1 and trigonal 3 T polytypes of phengitic micas synthesized at 11 GPa and 900°C have been refined at ambient conditions...
FIGURES
Journal Article
Published: 01 May 2000
European Journal of Mineralogy (2000) 12 (3): 529–541.
... – that boron occurs not only in trigonal coordination, but is also located in the tetrahedral ring site. Thus, a provisional structural formula is derived as (Na 0.65 □ 0.35 ) (Al 2.72 □ 0.28 ) (Al 5.42 Si 0.58 ) [Si 3.73 B 2.27 O 18 ] (BO 3 ) 3 (OH) 3.87 O 0.13 . In this synthetic olenite the OH-content...
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Published: 01 January 2013
DOI: 10.1180/DHZ.22
EISBN: 9780903056434
... are of economic importance. The following sections deal with the most common micas; muscovite, paragonite, glauconite, phlogopite, biotite, lepidolite and zinnwaldite. For the most part each is a distinct mineral which does not form a complete solid-solution series with any of the others, but phlogopite...
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Published: 01 January 2013
DOI: 10.1180/DHZ.11
EISBN: 9780903056434
...), one trigonal, have also been identified; the polymorphism can be described in terms of displacements across the L 1 layer and slight displacements in the L 2 layer. The main compositional variations shown by chloritoid are related to the substitutions (Mg,Mn) ↔ Fe 2+ and Fe 3+ ↔ Al. The amount...
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Journal Article
Published: 01 January 2002
Reviews in Mineralogy and Geochemistry (2002) 46 (1): 99–116.
... methods by Guggenheim et al. (1987) and Catti et al. (1989) for muscovite, by Comodi and Zanazzi (2000) for paragonite, and by Amisano Canesi et al. (1994) for phengite. Symmes (1986) reported isobaric expansion data from the powder diffraction method for muscovite, paragonite, margarite...
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Published: 01 January 2013
EISBN: 9780903056434
... sheet is di-trigonal rather than hexagonal, and the vacant M 1 octahedra (unshaded and marked by small black squares) are larger than the other octahedra (below shaded tetrahedra), which are occupied by Al (after Bailey, 1984 and Fleet, 2003, Rock-Forming Minerals , 3A , Micas , Geol. Soc., London...
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Journal Article
Published: 01 March 2000
American Mineralogist (2000) 85 (3-4): 586–592.
... of a nearly trigonal dipyramid. The presence of Al in fivefold coordination has been reported by Udawaga et al (1974) in a muscovite dehydroxylated after annealing in air; it was recently confirmed in paragonite dehydroxylated in the same way at 600 °C (P. Comodi, personal communication; Comodi and Zanazzi...
FIGURES
Journal Article
Published: 01 January 2002
Reviews in Mineralogy and Geochemistry (2002) 46 (1): 351–369.
.... Simple mass ratio calculations on the basis of a band at 112 cm −1 for muscovite and at 98 cm −1 for paragonite show that there is a problem with the assumption of a simple interlayer ion stretching vibration. The substitution of Si by Al in dioctahedral K-mica causes an increase of the band position...
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Journal Article
Published: 01 January 2002
Reviews in Mineralogy and Geochemistry (2002) 46 (1): 117–153.
... ordering may be lower than the ideal one described by the trigonal model as a function of the concrete stacking mode in a polytype: this phenomenon is known as desymmetrization ( Durovic 1979 ). A primitive P lattice for the layer occurs in the unique example of anandite-2 O (space group Pnmn...
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Journal Article
Published: 01 May 2009
American Mineralogist (2009) 94 (5-6): 793–800.
... chose two more high-symmetry reference materials, prepared by ion thinning of standard petrographic thin sections. These were quartz and vesuvianite (trigonal and tetragonal, respectively). The quartz specimen was a (001) section cut from a centimeter-size, transparent crystal; the expected lattice...
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Journal Article
Published: 01 January 2002
Reviews in Mineralogy and Geochemistry (2002) 46 (1): 155–279.
... and challenging points. Although the causes of the complexity of the phenomenon of polytypism in micas are multifaceted, they can be simplified to “magic words”, local (partial) symmetry , and a “magic number”, 3. As shown hereafter, each atomic plane in mica has an ideal symmetry of at least trigonal...
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Journal Article
Journal: Elements
Published: 01 February 2021
Elements (2021) 17 (1): 17–22.
... the stability fields of paragonite and of glaucophane were exceeded for such compositions. Coesite has been found in these units, mainly as inclusions in garnet. The peak P–T conditions for the Brossasco–Isasca Unit are estimated at either ~790 °C and ~3.7 GPa ( Chopin and Schertl 1999 ) or ~730 °C and ~4.0...
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Journal Article
Published: 01 February 2004
American Mineralogist (2004) 89 (2-3): 467–471.
... nomenclature system for amphiboles, occurs as relicts in association with clinopyroxene, garnet, rutile, apatite, paragonite, plagioclase, and other amphiboles in a kyanite- bearing eclogite from the Jianchang eclogite pod in the Jiangsu and Shandong provinces of eastern China. Type material is in the Museo di...
Journal Article
Published: 01 January 2002
Reviews in Mineralogy and Geochemistry (2002) 46 (1): 1–97.
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Journal Article
Published: 01 August 2012
American Mineralogist (2012) 97 (8-9): 1460–1468.
... the structure refinements of the studied micas and of the literature dioctahedral 2 M 2 and 2 M 1 micas Musc _4 Tob_7 2 M 2 -phengite * 2 M 2 -nanpingite † 2 M 1 -paragonite ‡ 2 M 1 -muscovite § 2 M 1 -muscovite || t tet (Å) 2.221 2.205 2.208 2.216 2.216 2.220 2.226 t...
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Journal Article
Journal: Geology
Published: 01 November 2016
Geology (2016) 44 (11): 899–902.
... of temperature, pH, and phase partitioning ( Konrad-Schmolke and Halama, 2014 ; Wunder et al., 2005 ). Interestingly, 11 B is preferentially partitioned in phases with trigonal coordination (fluids), whereas 10 B is mainly partitioned in phases with tetrahedral coordination (solids) ( Peacock and Hervig, 1999...