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Gas-mediated trace element incorporation into rhyolite-hosted topaz: A synchrotron microbeam XAS study

Journal Article · · American Mineralogist
DOI:https://doi.org/10.2138/am-2022-8417· OSTI ID:2440591
 [1];  [1];  [1];  [1];  [2]
  1. Stony Brook Univ., NY (United States)
  2. Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
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Magmatic gas exsolving during late-stage cooling of shallow magmas has been considered an important facilitator of low-pressure alteration and metal transport. However, the chemical properties of such gas, particularly its metal transport mechanisms and capacity, remain elusive. Trace elements in minerals produced by gas-mediated surface reaction or precipitation from gas capture details of gas composition and reaction pathways. However, interpretation of mineral trace element contents is dependent on understanding crystallographic controls on gas/mineral partitioning. Here, this work investigates the structural accommodation of As, Mn, Ga, Ge, Fe, and Ti in vapor-deposited topaz of vesicular topaz rhyolite from the Thomas Range, Utah, through single-crystal synchrotron microbeam X-ray techniques on picogram quantities of those trace elements. X-ray absorption near edge structure (XANES) data indicates that these elements are incorporated into topaz as As5+, Fe3+, Mn3+, Ti4+, Ga3+, and Ge4+. Extended X-ray absorption fine structure (EXAFS) analysis for these trace elements, compared to EXAFS of structural Al and Si, reveals that As5+ and Ge4+ are incorporated directly into the tetrahedral site of the topaz structure, with the octahedral site accommodating Mn3+, Fe3+, Ga3+, and Ti4+. For As5+ and Fe3+, the structural impact of substitution extends to at least second neighbors (other elements were only resolvable to first neighbors). Further interpretation of the EXAFS results suggests that the substitution of Ti4+ results in increased distortion of the octahedral site, while the other trace elements induce more uniform expansion correlating in magnitude to their ionic radius. Comparison of quantified X-ray fluorescence (XRF) data for two topaz crystals from this rhyolite reveals variable trace element concentrations for As5+, Fe3+, Ga3+, and Ti4+, reflective of a source gas undersaturated in these trace elements changing in concentration over the period of topaz deposition. The identical Ge4+ content of the two topaz crystals suggests that Ge4+ in the gas was buffered by the growth of another Ge4+-bearing phase, such as quartz. The very low Mn3+ content in the topaz crystals does not reflect the abundance of Mn3+ in the gas (saturation of Mn is evidenced by coexisting bixbyite). Instead, it suggests a strong Jahn-Teller inhibitory effect to the substitution of Mn3+ for Al3+ in the distorted octahedral site of topaz. It is proposed that exsolution of an HF-enriched gas from cooling rhyolitic magma led to local scouring of Al, Si, and trace metals from the magma. Once topaz crystals nucleated, self-catalyzed reactions that recycle HF led to continued growth of topaz.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
Grant/Contract Number:
SC0012704; AC02-98CH10886
OSTI ID:
2440591
Report Number(s):
BNL--226044-2024-JAAM
Journal Information:
American Mineralogist, Journal Name: American Mineralogist Journal Issue: 12 Vol. 108; ISSN 0003-004X
Publisher:
Mineralogical Society of AmericaCopyright Statement
Country of Publication:
United States
Language:
English

References (29)

Elemental analysis of topaz from northern areas of Pakistan and assessment of induced radioactivity level after neutron irradiation for color induction journal October 2010
Germanium crystal chemistry in hematite and goethite from the Apex Mine, Utah, and some new data on germanium in aqueous solution and in stottite journal March 1987
Relationship between the structure and growth morphology of topaz [Al2SiO4(F,OH)2] using the periodic bond chain method journal December 1995
Experimental study of arsenic speciation in vapor phase to 500°C: implications for As transport and fractionation in low-density crustal fluids and volcanic gases journal October 2002
Crystallisation of magmatic topaz and implications for Nb–Ta–W mineralisation in F-rich silicic melts — The Ary-Bulak ongonite massif journal August 2014
Jahn-Teller distortion of Mn3+-occupied octahedra in red beryl from Utah indicated by optical spectroscopy journal January 2018
Metallogenesis of germanium—A review journal March 2007
Jahn–Teller distortions in transition metal compounds, and their importance in functional molecular and inorganic materials journal January 2013
Structural and electronic evolution of the As(OH)3 molecule in high temperature aqueous solutions: An x-ray absorption investigation journal November 2004
The Crystal Structure of Topaz journal August 1928
Ti K -edge XANES studies of Ti coordination and disorder in oxide compounds: Comparison between theory and experiment journal July 1997
ATHENA , ARTEMIS , HEPHAESTUS : data analysis for X-ray absorption spectroscopy using IFEFFIT journal June 2005
The TES beamline (8-BM) at NSLS-II: tender-energy spatially resolved X-ray absorption spectroscopy and X-ray fluorescence imaging journal October 2019
Germanium in Magnetite: A Preliminary Review journal April 2017
Spectroscopic study of natural gem quality "Imperial"-Topazes from Ouro Preto, Brazil journal July 2003
Topaz as an important host for Ge in granites and greisens journal June 2013
29Si solid state NMR and Ti K-edge XAFS pre-edge spectroscopy reveal complex behavior of Ti in silicate melts journal March 2020
Characterizing Trace Metal Impurities in Optical Waveguide Materials Using X-Ray Absorption journal January 1998
A cathodoluminescence-assisted LA-ICP-MS study of topaz from different geological settings journal January 2018
Epithermal beryllium deposits in water-laid tuff, western Utah journal April 1977
Topaz rhyolites; distribution, origin, and significance for exploration journal December 1982
Use of multivariate analysis for synchrotron micro-XANES analysis of iron valence state in amphiboles journal May 2016
A Cr3+ luminescence study of natural topaz Al2SiO4(F,OH)2 up to 60 GPa journal November 2019
Arsenic speciation in fluid inclusions using micro-beam X-ray absorption spectroscopy journal June 2010
Amorphous Materials: Properties, Structure, and Durability: Arsenic enrichment in hydrous peraluminous melts: Insights from femtosecond laser ablation-inductively coupled plasma-quadrupole mass spectrometry, and in situ X-ray absorption fine structure spectroscopy journal June 2010
Calculation of multicomponent chemical equilibria in gas-solid-liquid systems; calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mount St. Helens journal October 1993
On the chemical composition and related physical properties of topaz journal May 1894
Gallium and germanium geochemistry during magmatic fractionation and post-magmatic alteration in different types of granitoids: a case study from the Bohemian Massif (Czech Republic) journal June 2013
Pegmatitic Beryl as Indicator of melt Evolution: Example from the Velasco District, Pampeana Pegmatite Province, Argentina, and Review of Worldwide Occurrences journal October 2014

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Related Subjects

36 MATERIALS SCIENCE
EXAFS
XAFS spectra
XANES spectra
arsenic
coordination
crystal chemistry
crystal structure
crystallography
fluorides
gases
germanium
halides
igneous rocks
metals
nesosilicates
octahedra
orthosilicates
polyhedra
rhyolites
silicates
spectra
spectroscopy
substitution
synchrotron radiation
topaz
trace elements
volcanic rocks
x-ray spectra