Showing papers in "American Mineralogist in 2023"
TL;DR: Mineral Informatics as mentioned in this paper is the next frontier for researchers working with mineral data, and it is a key next step in integrative mineralogical studies, where data science and informatics methods are used to extract, analyze and interpret this abundance of information to improve our understanding of the planetary bodies in our solar system and the role our planet's geosphere played in the origin and evolution of life.
Abstract: Abstract Minerals are information-rich materials that offer researchers a glimpse into the evolution of planetary bodies. Thus, it is important to extract, analyze, and interpret this abundance of information to improve our understanding of the planetary bodies in our solar system and the role our planet’s geosphere played in the origin and evolution of life. Over the past several decades, data-driven efforts in mineralogy have seen a gradual increase. The development and application of data science and analytics methods to mineralogy, while extremely promising, has also been somewhat ad hoc in nature. To systematize and synthesize the direction of these efforts, we introduce the concept of “Mineral Informatics,” which is the next frontier for researchers working with mineral data. In this paper, we present our vision for Mineral Informatics and the X-Informatics underpinnings that led to its conception, as well as the needs, challenges, opportunities, and future directions of the field. The intention of this paper is not to create a new specific field or a sub-field as a separate silo, but to document the needs of researchers studying minerals in various contexts and fields of study, to demonstrate how the systemization and enhanced access to mineralogical data will increase cross- and interdisciplinary studies, and how data science and informatics methods are a key next step in integrative mineralogical studies.
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TL;DR: The thermal behavior of vergasovaite, ideally Cu 3 O(SO 4 )(MoO 4 ), and its synthetic analogue has been studied by high-temperature single crystal X-ray diffraction in the temperature range of 21 300-1100 K as mentioned in this paper .
Abstract: 19 Thermal behavior of vergasovaite, ideally Cu 3 O(SO 4 )(MoO 4 ), and its synthetic analogue has 20 been studied by high-temperature single crystal X-ray diffraction in the temperature range of 21 300-1100 K. According to the EMPA results, the empirical formulas are 22 (
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TL;DR: In this paper , the authors used the Korringa-Kohn-Rostoker method combined with the coherent potential approximation (KKR-CPA) to compute the equation of states for face-centered cubic (fcc) FeH x .
Abstract: 11 Hydrogen is a strong candidate for light alloying elements in the terrestrial cores. 12 Previous first-principles studies on non-stoichiometric hexagonal close-packed (hcp) 13 and double hexagonal close-packed (dhcp) FeH x predicted a discontinuous volume 14 expansion across the magnetic phase transition from non-magnetic (NM) or 15 antiferromagnetic (AFM) to ferromagnetic (FM) state with increasing the hydrogen 16 content, x at 0 K. However, previous high pressure and temperature neutron diffraction 17 experiments on face-centered cubic (fcc) FeH x did not show such nonlinearity. The 18 discrepancy between theory and experiment may be due to differences in the crystal 19 structure, magnetism, or temperature. In this study, we computed the equation of states 20 for fcc FeH x by using the Korringa-Kohn-Rostoker method combined with the 21 coherent potential approximation (KKR-CPA). In addition to the four types of 22 ground-state magnetism (FM, AFM-I, AFM-II, and NM), we also calculated the local 23 magnetic disorder (LMD) state, which approximates the paramagnetic (PM) state with 24 local spin moment above the Curie temperature. The results show that even though FM, 25 AFM-I, AFM-II, and NM calculations predict a discontinuity in the volume at 0 K, the 26 volume becomes continuous above the Curie temperature, consistent with the previous 27 high-temperature experiment. From the enthalpy comparison at 0 K, FM fcc FeH ( x = 28 1) undergoes the NM state above ~48 GPa. The magnetic transition pressure decreases 29 with decreasing hydrogen content. Therefore, below the magnetic transition pressure, 30 local spin moments affect the density and elastic wave velocity of fcc FeH x , which may 31 be important for small terrestrial bodies such as Mercury and Ganymede. On the other 32 hand, at the Earth’s core pressure above 135 GPa, fcc FeH x becomes NM. Thus, we 33 calculated the density and bulk sound velocity as a function of pressure at 0 K for NM
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TL;DR: In this article , the authors proposed a method to solve the problem of the problem: this article ] of "uniformity" of the distribution of data points in the data set.
Abstract: Abstract
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TL;DR: In this article , the reproducibility of peak position measurements of Raman spectra from quartz and zircon inclusions and reference crystals was evaluated using a combination of 1, 2, or 3 peak positions for the ~128, ~206, and ~464 cm-1 peaks in quartz.
Abstract: Abstract Raman spectroscopy is widely used to identify mineral and fluid inclusions in host crystals, as well as to calculate pressure-temperature (P-T) conditions with mineral inclusion elastic thermobarometry, for example quartz-in-garnet barometry (QuiG) and zircon-in-garnet thermometry (ZiG). For thermobarometric applications, P-T precision and accuracy depend crucially on the reproducibility of Raman peak position measurements. In this study, we monitored long-term instrument stability and varied analytical parameters to quantify peak position reproducibility for Raman spectra from quartz and zircon inclusions and reference crystals. Our ultimate goal was to determine the reproducibility of calculated inclusion pressures (“Pinc”) and entrapment pressures (“Ptrap”) or temperatures (“Ttrap”) by quantifying diverse analytical errors, as well as to identify optimal measurement conditions and provide a baseline for interlaboratory comparisons. Most tests emphasized 442 nm (blue) and 532 nm (green) laser sources, although repeated analysis of a quartz inclusion in garnet additionally used a 632.8 nm (red) laser. Power density was varied from <1 to >100 mW and acquisition time from 3 to 270s. A correction is proposed to suppress interference on the ~206 cm–1 peak in quartz spectra by a broad nearby (~220 cm–1) peak in garnet spectra. Rapid peak drift up to 1 cm–1/h occurred after powering the laser source, followed by minimal drift (<0.2 cm–1/h) for several hours thereafter. However, abrupt shifts in peak positions as large as 2–3 cm–1 sometimes occurred within periods of minutes, commonly either positively or negatively correlated to changes in room temperature. An external Hg-emission line (fluorescent light) can be observed in spectra collected with the green laser and shows highly correlated but attenuated directional shifts compared to quartz and zircon peaks. Varying power density and acquisition time did not affect Raman peak positions of either quartz or zircon grains, possibly because power densities at the levels of inclusions were low. However, some zircon inclusions were damaged at higher power levels of the blue laser source, likely because of laser-induced heating. Using a combination of 1, 2, or 3 peak positions for the ~128, ~206, and ~464 cm–1 peaks in quartz to calculate Pinc and Ptrap showed that use of the blue laser source results in the most reproducible Ptrap values for all methods (0.59 to 0.68 GPa at an assumed temperature of 450 °C), with precisions for a single method as small as ±0.03 GPa (2σ). Using the green and red lasers, some methods of calculating Ptrap produce nearly identical estimates as the blue laser with similarly good precision (±0.02 GPa for green laser, ±0.03 GPa for red laser). However, using 1- and 2-peak methods to calculate Ptrap can yield values that range from 0.52 ± 0.06 to 0.93 ± 0.16 GPa for the green laser, and 0.53 ± 0.08 GPa to 1.00 ± 0.45 GPa for the red laser. Semiquantitative calculations for zircon, assuming a typical error of ±0.25 cm–1 in the position of the ~1008 cm–1 peak, imply reproducibility in temperature (at an assumed pressure) of approximately ±65 °C. For optimal applications to elastic thermobarometry, analysts should: (1) delay data collection approximately one hour after laser startup, or leave lasers on; (2) collect a Hg-emission line simultaneously with Raman spectra when using a green laser to correct for externally induced shifts in peak positions; (3) correct for garnet interference on the quartz 206 cm–1 peak; and either (4a) use a short wavelength (blue) laser for quartz and zircon crystals for P-T calculations, but use very low-laser power (<12 mW) to avoid overheating and damage or (4b) use either the intermediate wavelength (green; quartz and zircon) or long wavelength (red; zircon) laser for P-T calculations, but restrict calculations to specific methods. Implementation of our recommendations should optimize reproducibility for elastic geothermobarometry, especially QuiG barometry and ZiG thermometry.
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TL;DR: In this paper , secondary-ion mass spectrometry (SIMS) measurements of the olivine standards of Bell et al. (2003, hereafter Bell03) and Withers et al., were compared to the independent nuclear reaction analysis (NRA) in Bell03 and elastic recoil detection analysis (ERDA), and they found that the measured Bell03 standards have issues of reproducibility and accuracy due to the presence of hydrous inclusions.
Abstract: Abstract Trace concentrations of H2O in olivine strongly affect diverse mantle and magmatic processes. H2O in olivine has been difficult to accurately quantify due to challenges in sample preparation and measurement, as well as significant uncertainties in standard calibrations. Here we directly compare secondary-ion mass spectrometry (SIMS) measurements of the olivine standards of Bell et al. (2003, hereafter Bell03) and Withers et al. (2012, hereafter Withers12) upon which most SIMS and Fourier transform infrared (FTIR) spectroscopy analyses are based. In the same SIMS session, we find that the olivine standards from the two studies are offset by ~50%, forming lines of different slope when comparing SIMS measurements to the independent nuclear reaction analysis (NRA) in Bell03 and elastic recoil detection analysis (ERDA) in Withers12. This offset is similar to the ~40% offset that exists in the FTIR absorption coefficients determined by those two studies, and points to the NRAERDA data as the cause for the offset more than different IR absorption characteristics of the different olivines. We find that the Withers12 olivine standards form the most precise calibration line, and that the measured Bell03 olivine standards have issues of reproducibility and accuracy due to the presence of hydrous inclusions (as documented previously by Mosenfelder et al. 2011). Owing to the limited availability of the Withers12 olivine standards, however, we recommend using orthopyroxene standards (Kumamoto et al. 2017) to calibrate H2O in olivine by SIMS due to similar calibration slopes. We revise the reference values of current orthopyroxene standards to account for uncertainties in the Bell et al. (1995) manometry data. With these revised values, the orthopyroxene calibration line is within 12% of the Withers12 olivine line, which is within the long-term uncertainty of the SIMS olivine measurements. We apply our SIMS calibration protocol to revise estimates of the partition coefficients for H2O between olivine and melt, resulting in a value of 0.0009 ± 0.0003 at pressures ~0.2–2 GPa. This brings into closer agreement between the partition coefficients determined from experimental studies and those based on natural studies of olivine-hosted melt inclusions.
TL;DR: In this paper , the authors proposed a method to solve the problem of homonymity in homonym identification, i.e., homonymization, in the context of homology.
Abstract: ABSTRACT
TL;DR: In this paper , a hydrothermal quartz vein with REE-U-Au mineralization in the Zimná Voda (Gemeric Unit, Western Carpathians, Slovakia) is associated with contact metamorphism between Permian granites and host phyllites and metaquartzites.
Abstract: Abstract A hydrothermal quartz vein with REE-U-Au mineralization in the Zimná Voda (Gemeric Unit, Western Carpathians, Slovakia) is associated with contact metamorphism between Permian granites and host phyllites and metaquartzites. It contains unique REE minerals of the monazite and xenotime groups. Monazite-(Ce), monazite-(Nd), monazite-(Sm), and Gd-dominant monazite [“monazite-(Gd)”], along with xenotime-(Y) to Gd-dominant xenotime [“xenotime-(Gd)”] and Gd-rich hingganite-(Y) show heterogeneous compositions and reflect a strong fractionation trend toward the enrichment of MREE (Sm to Dy), particularly Gd. Here, the gadolinium abundance reported in “monazite-(Gd)” (≤23.4 wt% Gd2O3) and Gd-rich xenotime-(Y) to “xenotime-(Gd)” (≤28.7 wt% Gd2O3) and accompanied by Gd-rich hingganite-(Y) (≤15.8 wt% Gd2O3), is among the highest Gd concentrations ever reported in natural minerals. The Gd-richest compositions show the following formulas: (Gd0.31Sm0.24 Nd0.15Ce0.10La0.05Dy0.03Y0.03...)0.98PO4 [“monazite-(Gd)”], (Gd0.36Y0.32Dy0.13Sm0.08Tb0.05...)0.98 (P0.96As0.04)1.00O4 [“xenotime-(Gd)”] and (Y0.71Gd0.43Dy0.23Sm0.22Tb0.06Er0.04Nd0.06...Ca0.06)1.96 ( ◻ 0.87 Fe 0.13 2 + ) 1.00 ( B e 1.82 B 0.18 ) 2.00 ( S i 1.90 A s 0.10 ) 2.00 O 8 ( O H 1.70 O 0.30 ) 2.00 ${{({{\square }_{0.87}}\,\text{Fe}_{0.13}^{2+})}_{1.00}}{{(\text{B}{{\text{e}}_{1.82}}\,{{\text{B}}_{0.18}})}_{2.00}}\,{{(\text{S}{{\text{i}}_{1.90}}\text{A}{{\text{s}}_{0.10}})}_{2.00}}\,\,{{\text{O}}_{8}}{{(\text{O}{{\text{H}}_{1.70}}\,{{\text{O}}_{0.30}})}_{2.00}}$ [hingganite-(Y)]. The MREE-rich monazites, xenotimes, and hingganite-(Y) precipitated in response to the alteration of primary uraninite, brannerite, and fluorapatite by low-temperature hydrothermal fluids of heterogeneous compositions on a microscale. These are responsible for the strong enrichment of individual MREE, especially Gd in the secondary minerals. This is accompanied by the advancing development of the W-type tetrad effect on REE through monazite species. The substantial incorporation of Gd into both REE-selective monazite and xenotime structures that are accompanied by LREE vs. HREE segregation indicates the possibility of differently sized REE3+ miscibility in REEPO4 solid solutions, as well as the stabilization of the Gd-rich orthophosphate structure by substitution of the remaining A-site cations with smaller HREE+Y in the xenotime-type, and/or larger LREE in the monazite-type structure.
TL;DR: In this paper , the authors proposed a method to solve the problem of the problem: this paper ] of "uniformity" of the distribution of data points in the data set.
Abstract: Abstract
TL;DR: In this article , the origin of the common blue 450 nm (2.8 eV) cathodoluminescence (CL) emission in natural and synthetic quartz has been investigated by a combination of microscopy and spectroscopy, electron paramagnetic resonance (EPR), and trace-element analysis by microprobe analysis as well as inductively coupled plasma-mass spectrometry (ICP-MS).
Abstract: The origin of the common blue 450 nm (2.8 eV) cathodoluminescence (CL) emission in natural and synthetic quartz has been investigated by a combination of CL microscopy and spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and trace-element analysis by microprobe analysis as well as inductively coupled plasma-mass spectrometry (ICP-MS). The study shows that the appearance of the ~450 nm emission band can be attributed to two different defects in quartz. Firstly, a transient luminescence can be explained by structural defects in oxygen deficient quartz. The luminescence model implies self-trapped exciton (STE) emission related to oxygen vacancies. This type of CL emission is frequent in high-purity synthetic quartz and natural quartz of hydrothermal origin. Secondly, in Ti-rich quartz from natural samples (e.g. quartz phenocrysts in rhyolites) and synthetic quartz of Ti-diffusion experiments, an additional 450 nm (2.8 eV) emission was detected which is stable under the electron beam. The intensity of this ~450 nm emission band correlates with the
TL;DR: In this article , the authors used ultrafast optical pump-probe spectroscopy combined with an externally-heated diamond anvil cell to precisely determine the high pressure-temperature thermal conductivity of aluminous garnets.
Abstract: 8 Aluminous garnets [(Mg,Fe,Ca) 3 Al 2 (SiO 4 ) 3 ] are a key mineral group in Earth’s interior. Their 9 thermal conductivity under relevant chemical compositions and high pressure-temperature ( P-T ) 10 conditions plays a crucial role in affecting the thermal states of pyrolitic mantle and subducted 11 basaltic crust over the depth range they are present. Using ultrafast optical pump-probe 12 spectroscopy combined with an externally-heated diamond anvil cell, we have precisely 13 determined the high P-T thermal conductivity of aluminous garnets, including pyrope, grossular, 14 and pyrope-almandine solid solution. We find that the variable chemical composition has minor 15 effects on the thermal conductivity of these garnets over the P-T range we studied. Combined with 16 previous results, we provide new depth-dependent thermal conductivity profiles for a pyrolitic 17 mantle and a subducted basaltic crust. These important results significantly benefit geodynamics 18 simulations and advance our understanding of the thermal structure and evolution dynamics in 19 Earth’s upper mantle and transition zone. In addition, as garnets are also a key, useful material 20 family for modern technology, our results on the thermal property of natural garnets also shed 21 lights on the novel design of optical and electronic devices based on a variety of synthetic 22 nonsilicate garnets.
TL;DR: Yan and Ruizhong Hu as mentioned in this paper performed SEM and FIB-TEM analyses on nanoparticulate arsenian pyrite and found that 2 Au enrichment in the Carlin-type giant Lannigou gold deposit in SW China.
Abstract: Revision 2: 1 SEM and FIB-TEM analyses on nanoparticulate arsenian pyrite: implications for 2 Au enrichment in the Carlin-type giant Lannigou gold deposit in SW China 3 Jun Yan, Ruizhong Hu *, Jean S. Cline, Shanling Fu, Shirong Liu 4 1 State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, 5 Chinese Academy of Sciences, Guiyang 550081, China 6 2 College of Earth and Planetary Sciences, University of Chinese Academy of 7 Sciences, Beijing 100049, China 8 3 University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA 9
TL;DR: In this paper , a micro-scale non-destructive analytical technique to characterize the combined mineralogy, chemical composition of iron oxides and oxyhydroxides was proposed, which showed promise as superconductor materials and as repositories of paleoenvironmental information.
Abstract: Iron oxides and oxyhydroxides show promise as superconductor materials and as repositories of paleoenvironmental information. However, there are no microscale nondestructive analytical techniques to characterize their combined mineralogy, chemical composition
TL;DR: In this article , the authors measured quartz solubility in H 2 O-CaCl 2 solutions at 0.6-1.4 GPa, 600-900 ° C, and salt concentrations to 50 mol%.
Abstract: Fluid-mediated calcium metasomatism is often associated with strong silica mobility and the presence of chlorides in solution. To help quantify mass transfer at lower crustal and upper mantle conditions, we measured quartz solubility in H 2 O-CaCl 2 solutions at 0.6-1.4 GPa, 600-900 ° C, and salt concentrations to 50 mol%. Solubility was determined by weight loss of single-crystals using hydrothermal piston-cylinder methods. All experiments were conducted at salinity lower than salt saturation. Quartz solubility declines exponentially with added CaCl 2 at all conditions investigated, with no significant evidence for complexing between silica and Ca. The decline in solubility is similar to that in H 2 O-CO 2 but substantially greater than that in H 2 O-NaCl at the same pressure and temperature. At each temperature, quartz solubility at low salinity ( X CaCl2 < 0.1) depends strongly on pressure, whereas at higher X CaCl2 it is nearly pressure independent. This behavior is consistent with a transition from an aqueous solvent to a molten salt near X CaCl2 ~ 0.1. The solubility data were used to develop a thermodynamic model of H 2 O-CaCl 2 fluids. Assuming an ideal molten salt behavior and utilizing previous models for
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TL;DR: In this article , 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 18 elements.
Abstract: 9 Magmatic gas exsolving during late-stage cooling of shallow magmas has been considered an 10 important facilitator of low-pressure alteration and metal transport. However, the chemical 11 properties of such gas, particularly its metal transport mechanisms and capacity, remain elusive. 12 Trace elements in minerals produced by gas-mediated surface reaction or precipitation from gas 13 capture details of gas composition and reaction pathways. However, interpretation of mineral 14 trace element contents is dependent on understanding crystallographic controls on gas/mineral 15 partitioning. This work investigates the structural accommodation of As, Mn, Ga, Ge, Fe, and Ti 16 in vapor-deposited topaz of vesicular topaz rhyolite from the Thomas Range, Utah, through 17 single-crystal synchrotron microbeam X-ray techniques on picogram quantities of those trace 18 elements. X-ray absorption near edge structure (XANES) data indicates that these elements are 19 incorporated into topaz as As 5+ , Fe 3+ , Mn 3+ , Ti 4+ , Ga 3+ , and Ge 4+ . Extended X-ray absorption fine 20 structure (EXAFS) analysis for these trace elements, compared to EXAFS of structural Al and 21 Si, reveals that As 5+ and Ge 4+ are incorporated directly into the tetrahedral site of the topaz 22