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guyanaite

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Journal Article
Published: 01 July 2014
American Mineralogist (2014) 99 (7): 1277–1283.
...Daniel J. Schulze; Roberta L. Flemming; Patrick H.M. Shepherd; Herwart Helmstaedt Abstract Guyanaite, naturally occurring β-CrOOH, has been identified in a xenolith of Cr-rich omphacitite from the Moses Rock diatreme in the Navajo Volcanic Field of the southwestern United States. It occurs...
FIGURES
Journal Article
Published: 01 September 2012
European Journal of Mineralogy (2012) 24 (5): 839–850.
...Sandro Jahn; Bernd Wunder; Monika Koch-Müller; Leïla Tarrieu; Michael Pöhle; Anke Watenphul; Michael N. Taran Abstract Guyanaite, β-CrOOH, is a structural analogue of the high-pressure oxyhydroxide phases δ-AlOOH and ɛ-FeOOH. Here, it was synthesized in piston-cylinder and multi-anvil press...
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Field of likely equilibration conditions of <span class="search-highlight">guyanaite</span>-bearing xenolith (rou...
Published: 01 July 2014
Figure 3 Field of likely equilibration conditions of guyanaite-bearing xenolith (rounded rectangle with dark shading). Black dots are estimated equilibration conditions of three phengite eclogites from Smith et al. (2004) . Stability field of guyanaite relative to eskolaite + water (region
Image
SEM image showing the morphology of <span class="search-highlight">guyanaite</span> and coesite synthesized at 4 ...
Published: 01 September 2012
Fig. 2 SEM image showing the morphology of guyanaite and coesite synthesized at 4 GPa and 600 °C in run LT4 ( Table 1 ).
Journal Article
Published: 01 September 2016
American Mineralogist (2016) 101 (9): 1986–1995.
... goethite, two-line ferrihydrite, and nanophase FeOOH with guyanaite structure. Z-contrast images of the Fe-oxyhydroxides show ordered FeOOH nano-domains with guyanaite structure intergrown with nanophase goethite. The FeOOH nanophase is a precursor to the goethite. Henceforth, we will refer to it as “proto...
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Journal Article
Published: 01 March 2001
American Mineralogist (2001) 86 (3): 312–317.
...Kevin M. Rosso; James R. Rustad Abstract Plane wave pseudopotential methods are used to investigate the structures and total energies of AlOOH and FeOOH in the five canonical oxyhydroxide structures: diaspore (goethite), boehmite (lepidocrocite), akaganeite, guyanaite, and grimaldiite. The local...
FIGURES
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Fundamental octahedra for ( a ) boehmite/lepidocrocite; ( b ) grimaldiite; ...
Published: 01 March 2001
F igure 2. Fundamental octahedra for ( a ) boehmite/lepidocrocite; ( b ) grimaldiite; ( c ) guyanaite; ( d ) diaspore/goethite; ( e ) akaganeite. Bond lengths and angles are defined and listed in Table 1 .
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Polyhedral frameworks for ( a ) boehmite/lepidocrocite viewed down [100]; (...
Published: 01 March 2001
F igure 1. Polyhedral frameworks for ( a ) boehmite/lepidocrocite viewed down [100]; ( b ) grimaldiite [100]; ( c ) guyanaite [001]; ( d ) diaspore/goethite [010] (Pnma setting); ( e ) akaganeite [001]. Dark spheres represent oxygen atoms, light spheres represent hydrogen atoms.
Image
Backscatter electron (BSE) image of a portion of a cluster of accessory min...
Published: 01 July 2014
Figure 1 Backscatter electron (BSE) image of a portion of a cluster of accessory minerals in sample 12-90-50. Phases labeled are guyanaite (guy), eskolaite (es), carmichaelite (carm), and chromite (cht). These phases are set in a matrix of omphacite that appears very dark gray in this image
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In situ μXRD of accessory minerals from clusters in sample 12-90-50. ( a ) ...
Published: 01 July 2014
data; the bright spots indicate larger crystallites and streaks indicate slight dispersion of crystallite orientation likely due to intergrowth of kosmochlor (kos) and guyanaite (guy). The absence of complete Debye rings indicates that these crystallites do not occur in a random distribution
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Pressure-Temperature diagram showing experimental results from this study (...
Published: 01 September 2012
Fig. 3 Pressure-Temperature diagram showing experimental results from this study ( P ≥ 4 GPa) and from Tombs et al. (1964) and Nørlund Christensen et al. (1976) ( P < 0.3 GPa). Filled squares represent synthesis of guyanaite, open squares represent formation of eskolaite
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fEDT screening on two crystal aggregates. In the two boxes the bright-field...
Published: 01 December 2016
, 11.5 = 11.5 Å phase, Gu = guyanaite). All the investigated crystals have a size of 500 nm or smaller and are in contact with other crystals requiring a remarkable goniometer for an automatic fEDT data collection. (Color online.)
Journal Article
Published: 01 September 2012
European Journal of Mineralogy (2012) 24 (5): 775–776.
... transitions in ilvaite (Koch-Müller et al.), and a combined computational and experimental investigation of pressure-induced hydrogen-bond symmetrization in guyanaite (Jahn et al.). Wentzcovitch et al. present a thorough state of the art review of the interpretation of pressure-induced Fe spin crossover...
Journal Article
Published: 01 December 2016
American Mineralogist (2016) 101 (12): 2645–2654.
..., 11.5 = 11.5 Å phase, Gu = guyanaite). All the investigated crystals have a size of 500 nm or smaller and are in contact with other crystals requiring a remarkable goniometer for an automatic fEDT data collection. (Color online.) ...
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Journal Article
Journal: Geology
Published: 01 August 2015
Geology (2015) 43 (8): 727–730.
... of the Colorado Plateau uplift: Initial constraints from vesicular basalt-derived paleoelevations : Geology , v. 30 , p. 807 – 810 , doi:10.1130/0091-7613(2002)030<0807:TOCPUI>2.0.CO;2. Schulze D.J. Flemming R.L. Shepherd P.H.M. Helmstaedt H. , 2014 , Mantle-derived guyanaite...
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Journal Article
Published: 01 November 2019
Russ. Geol. Geophys. (2019) 60 (11): 1229–1246.
... in mantle inclusions of omphacite pyroxenite, resulted from complex postmagmatic alteration of the host rock: metamorphism, metasomatism, as well as hydration and subsequent dehydration of guyanaite (a hydrous oxide) in a subduction setting at T 650–800 °C ( Schulze et al., 2014 ). Relatively low...
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Journal Article
Published: 01 June 2017
European Journal of Mineralogy (2017) 29 (3): 385–395.
... effects, the experiments could be ideally conducted on both AlOOD and AlOOH. Our results might also be relevant for other hydrous minerals, such as guyanaite ( Jahn et al. , 2012 ) or dense hydrous magnesium silicates ( Ohira et al. , 2014 ; Tsuchiya, 2013 ), where nuclear quantum effects...
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Journal Article
Published: 01 March 2016
American Mineralogist (2016) 101 (3): 706–712.
... . Physics and Chemistry of Minerals , 36 , 343 – 354 . Jahn S. Wunder B. Koch-Müller M. Tarrieu L. Pohle M. Watenphul A. Taran M.N. ( 2012 ) Pressure-induced hydrogen bond symmetrization in guyanaite, beta-CrOOH: evidence from spectroscopy and ab initio simulations...
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Journal Article
Published: 18 February 2022
Mineralogical Magazine (2022) 86 (2): 214–221.
... of Singhbhum North Orissa Eastern India . Geological Society of India , Memoir 27. Pp. 341. Schulze D.J. , Flemming R.L. , Shepherd P.H.M. and Helmstaedt H. ( 2014 ) Mantle-derived guyanaite in a Cr-omphacitite xenolith from Moses Rock diatreme, Utah . American Mineralogist , 99...
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Journal Article
Published: 01 June 2024
Russ. Geol. Geophys. (2024) 65 (6): 699–713.
..., CrO(OH) polymorphs: bracewellite, grimaldiite, and guyanaite, all with Cr 3+ , encountered in merumite (hydrothermally altered cinder and sandstone). These minerals can bear minor V but, judging by field and laboratory data, they crystallize at temperatures of 140 °C and higher, which rules out...
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