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Pressure-induced phase transitions in Ni-bearing ferrosilite (Ni-En31Fs65) Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Jingui Xu, Dawei Fan, Dongzhou Zhang, Bo Li, Wenge Zhou, Przemyslaw Dera
Orthopyroxene is an abundant mineral in subducting slabs. Studying its phase transitions at high pressure is important to the understanding of mineralogy of subducting slabs in the deep Earth. Synchrotron-based single-crystal X-ray diffraction experiments were conducted on a synthetic Ni-bearing ferrosilite (Ni-En31Fs65) at pressures up to 33.8 GPa. Three phase transitions were observed at 12.1(6)
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Interfacial interactions controlling adsorption of metal cations on montmorillonite Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Ke Jin Li, Alfin Kurniawan, Georgios E. Christidis, Jia Yong He, Chun Hui Zhou
Montmorillonite (Mt) is a ubiquitous swelling clay mineral and major component of soft rocks, sediments, and soils with an inherent capability to sorb metal cations. This unique feature renders Mt important for the enrichment and mobilization of environmentally important metal cations, retardation of heavy metals and radionuclide ions, the evolution of clay mineral itself, soils and sediments, and
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Microstructural and compositional evolutions during transformation from biotite to berthierine: Implications for phyllosilicate alteration processes Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Jiaxin Xi, Yiping Yang, Hongping He, Haiyang Xian, Wei Tan, Rui Li, Jianxi Zhu, Huifang Xu
The composition and microstructure of phyllosilicates are prone to transformation due to their great sensitivity to surrounding physicochemical changes. Berthierine [(R2+,R3+,☐)6(Si,Al)4O10(OH)8] (☐ represents octahedral vacancy) is a typical ferromagnesian phyllosilicate that commonly occurs in ferruginous rocks of shallow-marine habitats and has been used as an indicator of local depositional and/or
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Vapor-phases as Cu transport agents for the shear-zone-hosted mineralization system: A perspective from H-O-S-Cu isotopes Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Yun Zhao, Chunji Xue, Sheng-Ao Liu, Ryan Mathur, Xiaobo Zhao, Reimar Seltmann, Jiangang Jiao, Yongsen Huang, Xuefeng Wang
Elucidating metal transport agents is the key to understanding the genesis of deposits and tracking the locations of concealed orebodies. Here, we integrate H-O-S-Cu isotopic data from the shear-zone-hosted Lingyun Cu deposit, China, as a means to fingerprint metal transport agents. Sulfide mineralization can be divided into early and late stages, which consist of chalcopyrite + bornite + quartz veins
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Don Juan Basin, Antarctica: A chemically altering environment with martian analog potential Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Andrew B. Foerder, Peter A.J. Englert, Janice L. Bishop, Christian Koeberl, Zachary F.M. Burton, Shital Patel, Everett K. Gibson
The McMurdo Dry Valleys of Antarctica provide a testbed for alteration processes on Mars due to the cold, arid, and windy conditions. Analysis of three sediment cores collected from Don Juan Basin, Wright Valley, Antarctica, reveals that surface sediment formation is primarily dominated by physical alteration. Chemical alteration occurs sporadically in this region and is frequently indicated by the
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High-pressure polymorphs of ferroan dolomite: Possible host structures for carbon in the lower mantle Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Naira S. Martirosyan, Ilias Efthimiopoulos, Sandro Jahn, Sergey S. Lobanov, Richard Wirth, Hans-Josef Reichmann, Monika Koch-Müller
In this study, we investigated four different ferroan dolomite samples using in situ Raman spectroscopy and powder X-ray diffraction (XRD) at pressures up to 48 GPa and room temperature. Our results show that the transition from Dolomite-I (Dol-I) to Dolomite-II (Dol-II) occurs above 13–16 GPa, and the transition pressure depends on the composition of the solid solution. Compression above 32–35 GPa
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Revisiting the genesis of the adakite-like granitoids in collisional zones: Water-fluxed melting of intermediate to felsic rocks with dilution by low Sr/Y phases Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Yuan-Hui Xie, Joshua J. Schwartz, Xiao-Wei Li, Keda Cai, Bader Thomas, Huan Li, Fang-Yue Wang, Xiao-Bing Zhang, Xuan-Xue Mo, Guo-Chen Dong
High-Sr/Y granitoids in continental settings are sometimes erroneously regarded as the products derived from partial melting of thickened/delaminated mafic lower curst under relatively higher pressures (>1.5 GPa) in a collisional orogenic setting. In fact, multiple magmatic processes in the trans-crustal magma system, such as recycling of antecrysts, crustal assimilation, and fractional crystallization
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Thermoelastic properties of non-metamict zircon Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Marie Münchhalfen, Jürgen Schreuer
The thermoelastic properties and thermal expansion of natural single-crystal zircon without detectable radiation damage were determined in the temperature range between 100 and 1650 K on five samples from Cambodia, Sri Lanka, and Tanzania. Up to about 1500 K, the results are in excellent agreement and fully reversible. The average adiabatic elastic stiffness coefficients at room temperature in GPa
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Scheelite composition fingerprints pulsed flow of magmatic fluid in the Fujiashan W skarn deposit, eastern China Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 YunHao Ji, GuiQing Xie, Rolf L. Romer, Wei Li, QiaoQiao Zhu, Bin Fu
Scheelite (CaWO4) is an economically important W mineral in skarns that form when magmatic fluids exsolved from a granitic intrusion react with carbonate wall rocks. In the Fujiashan W skarn deposit, scheelite formed during four stages of the hydrothermal skarn development. We present cathodoluminescence (CL) images and in situ trace element and Sr-O isotope data of scheelite from these four stages
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Mineralogy of the 1.45 Ga Wafangzi manganese deposit in North China: Implications for pulsed Mesoproterozoic oxygenation events Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Hao Yan, Lingang Xu, Jingwen Mao, Dongjie Tang, Xiuqing Yang, Yinzeng Bai, Chao Li, Kurt O. Konhauser, Leslie J. Robbins
Ancient manganese (Mn) deposits are primarily characterized by the presence of Mn(II) carbonates that likely formed by the diagenetic reduction of precursor Mn(IV) oxides. As such, Precambrian sedimentary Mn deposits have been used as a line of evidence for the evolution of oxygen in Earth’s surface environments. However, recent studies have shown that these Mn(II)-carbonates have the ability to directly
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Tourmaline growth in the border and wall zones of the Emmons pegmatite (Maine, U.S.A.): Evidence for disequilibrium crystallization and boundary layer formation Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Laura M. van der Does, Niels Hulsbosch, Pim Kaskes, Jan Elsen, Philippe Claeys, Philippe Muchez, Mona-Liza C. Sirbescu
The anisotropic textures, including unidirectional solidification textures and graphic intergrowths, characteristic for pegmatites, are interpreted to result from disequilibrium crystallization at high degrees of undercooling. Experimental studies have revealed the existence of thin boundary layers surrounding the rapidly growing crystals. Here, tourmaline-bearing samples from the outer zones of the
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New Mineral Names Am. Mineral. (IF 3.1) Pub Date : 2024-04-01 Travis A. Olds, Christopher Emproto
This issue of New Mineral Names provides a summary of the newly described minerals from 2023 and selected information for recent descriptions from October to December of 2023. New mineral name trends and observations are presented using an objective, data-driven, and curated examination of new mineral species and their broader implications.A total of 112 new mineral species were approved in 2023; see
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A possible origin of the lunar spinel-bearing lithologies as told by the meteorite NWA 13191 Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Lan F. Xie, Hong Y. Chen, Bing K. Miao, Wen L. Song, Zhi P. Xia, Chuan T. Zhang, Guo Z. Chen, Jin Y. Zhang, Si Z. Zhao, Xu K. Gao
Pink spinel anorthosite (PSA) and pink spinel troctolite (PST) are two lunar lithologies known to contain Mg-rich spinel. PSA rich in spinel and lacking mafic minerals, was detected by the visible and near-infrared reflectance spectroscopy. PST clasts were found in returned lunar samples and meteorites. NWA 13191 is a recently approved lunar meteorite that contains a large amount of spinel-bearing
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Genetic implications, composition, and structure of trioctahedral micas in xenoliths related to Plinian eruptions from the Somma-Vesuvius volcano (Italy) Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Giuseppina Balassone, Emanuela Schingaro, Maria Lacalamita, Ernesto Mesto, Angela Mormone, Monica Piochi, Vincenza Guarino, Annamaria Pellino, Loredana D’Orazio
The present work is part of a systematic mineralogical and petrographic characterization of mica-bearing xenoliths from Somma-Vesuvius volcano (Roman Magmatic Province, southern Italy). Skarns, composite skarns-marbles and cumulates from Pompeii Plinian eruption (AD 79), and skarns and syenite from Avellino eruption (3945 ± 10 cal yr BP) were investigated to define the crystal chemistry of the Somma-Vesuvius
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Magmatic and hydrothermal controls on diverse Nb mineralization associated with carbonatite-alkaline complexes in the southern Qinling orogenic belt, Central China Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Rong-Lin Ma, Wei Terry Chen, Yan-Wen Tang
Although carbonatite-alkaline complexes are the primary source of the world’s niobium (Nb) supply, the mineralization style is largely variable in these complexes and the processes behind their formation are still poorly understood. Exemplifying with our new observations on the ~430 Ma Miaoya and Shaxiongdong carbonatite-syenite complexes in the southern Qinling orogenic belt, central China, show that
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Experimental study on the kinetics of magnesiohornblende dehydration and its implications Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Kenan Han, Li Yi, Duojun Wang, Ruixin Zhang, Peng Chen
Magnesiohornblende dehydration was studied using both high-temperature thermogravimetric analysis and high-pressure differential thermal analysis (HP-DTA). The high-temperature thermogravi-metric analysis results revealed that magnesiohornblende dehydration at high temperatures could be divided into three steps: 848–1058, 1058–1243, and 1243–1473 K, and each step followed an n-order reaction (Fn).
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Thermal behavior of borax, Na2B4O5(OH)4·8H2O Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Wataru Nishiyasu, Atsushi Kyono
Globally, borax is one of the most important borate minerals, both industrially and from a technological viewpoint. Despite its importance, there have been only a few reports on the structural changes of borax upon heating. In this study, we have investigated the thermal behavior and structural characteristics of borax using thermal analysis, in situ high-temperature synchrotron X-ray diffraction,
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A simple method for obtaining heat capacity coefficients of minerals Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Samuel Bowman, Arkajyoti Pathak, Vikas Agrawal, Shikha Sharma
Heat capacity data are unavailable or incomplete for many minerals at geologically relevant temperatures. Despite the availability of entropy and enthalpy values in numerous thermodynamic tables (even sometimes at elevated temperatures), there remains need for extrapolation beyond, or interpolation between, temperatures. This approach inevitably results in estimates for entropy and enthalpy values
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Molybdenum isotopic fractionation in the Panzhihua mafic layered intrusion in the Emeishan large igneous province, southwest China Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Le Zhang, Jie Li, Yan Zhang, Bing-Yu Peng, Zhi-Bing Wang, Zhong-Yuan Ren
The large Mo isotopic fractionations between different geological reservoirs make this isotopic system a potentially useful tool for constraining the origins of magmatism. However, the effect of magmatic differentiation on Mo isotopes is still controversial. In this study, we obtained Mo isotope data for the Panzhihua gabbroic intrusion (i.e., including mineral separates of clinopyroxene, plagioclase
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Halogen fractionation during vapor-brine phase separation revealed by in situ Cl, Br, and I analysis of scapolite from the Yixingzhai gold deposit, North China Craton Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Wen-Sheng Gao, Xiao-Dong Deng, Lei Chen, Li-Zhong Zhang, Yu-Xiang Li, Tao Luo, Jian-Wei Li
Halogens (Cl, Br, and I) are major complexing agents for metal ions, and their ratios (Br/Cl and I/Cl) have been used to determine the source and evolution of hydrothermal fluid. Halogen fractionation during hydrothermal fluid evolution, however, has been inferred from several studies, which poses problems in using halogen ratios as a fluid tracer. The Br/Cl and I/Cl ratios of scapolite are consistent
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The effects of oxygen fugacity and sulfur on the pressure of vapor-saturation of magma Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Ery C. Hughes, Philippa Liggins, Lee Saper, Edward M. Stolper
Geobarometers are commonly used to determine the pressure (and hence depth) of magmatic bodies. For instance, at equilibrium, the concentration of dissolved volatiles in a vapor-saturated melt can be used as a barometer: this is the pressure of vapor-saturation (Psatv). Most determinations of Psatv assume that melt and vapor contain only oxidized C-O-H species. However, sulfur is the third most abundant
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A revisit to the phase transition behavior of K-feldspar at high-pressure and high-temperature: Implications on metastable K-feldspar in cold subduction Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Chengcheng He, Heping Li
Felsic gneiss is a major type of ultrahigh-pressure metamorphic rock in continental subduction zones. As an important mineral of felsic gneiss, the phase behavior of K-feldspar is of great significance for studying subducting seismic activities, crust-mantle interactions, and plate tectonics in the Earth’s interior. In this study, we investigated the phase relations in K-feldspar using Raman spectroscopy
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Equation of state and structural evolution of manganese dolomite (kutnohorite) under high pressures Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Liangxu Xu, Weibin Gui, Kewei Shen, Dongzhou Zhang, Jingui Xu, Jin Liu
Understanding the structural evolution of carbonate minerals with increasing pressure is essential to decoding the role of Earth’s mantle in the global carbon cycle and long-term climate change. Here, we carried out synchrotron single-crystal X-ray diffraction measurements on a natural sample of manganese dolomite [kutnohorite, Ca1.11Mn0.89(CO3)2] in a diamond-anvil cell up to 51.2 GPa at room temperature
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Vergasovaite to cupromolybdite topotactic transformation with crystal shape preservation Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Evgeni V. Nazarchuk, Oleg I. Siidra, Dmitri O. Charkin, Gleb V. Nikolaevich, Artem S. Borisov, Valery L. Ugolkov
Thermal behavior of vergasovaite, ideally Cu3O(SO4)(MoO4), and its synthetic analog has been studied by high-temperature single-crystal X-ray diffraction in the temperature range of 300–1100 K. According to EMPA results, the empirical formulas are (Cu2.36Zn0.61)Σ2.97O[(Mo0.91S0.08V0.04)Σ1.03O4](SO4) for vergasovaite and Cu2.97O[(Mo0.92S0.09)Σ1.01O4](SO4) for its synthetic analog. The mineral is stable
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Thermal conductivity of aluminous garnets in Earth’s deep interior Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Yu-Ping Grace Hung, Yi-Chi Tsao, Chun-Hung Lin, Wen-Pin Hsieh
Aluminous garnets [(Mg,Fe,Ca)3Al2(SiO4)3] are a key mineral group in Earth’s interior. Their thermal conductivity with relevant chemical compositions and at high-pressure-temperature (P-T) conditions plays a crucial role in affecting the thermal states of pyrolytic mantle and subducted basaltic crust over the depth range they are present. Using ultrafast optical pump-probe spectroscopy combined with
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Interaction of seawater with (ultra)mafic alkaline rocks—Alternative process for the formation of aegirine Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Vladislav Rapprich, Dalibor Matýsek, Ondřej Pour, Jakub Jirásek, Jitka Míková, Tomáš Magna
Submarine mafic and relatively Na-poor alkaline rocks in the Outer Carpathians often contain aegirine, a sodic pyroxene usually found in differentiated alkaline rocks. Its presence in rocks that are too basic and Na-poor for its conventional magmatic appearance is linked to sodic alteration of submarine alkaline rocks. Aegirine crystals grow on altered rims of diopside, commonly with crystal-lographic
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Predicting olivine formation environments using machine learning and implications for magmatic sulfide prospecting Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Shengchao Xue, Yunyun Niu, Zhuosen Yao, Luyang Wang, Xiaohao Zhang, Qingfei Wang
Global volcanic and plutonic olivines record the compositional characteristics and physicochemical conditions of the parental magmas. Thus, they have significant potential for use as petrogenetic discriminators of the olivine formation environment and prospecting indicators for potential host rocks of magmatic sulfide deposits. Several data visualization approaches have been proposed by researchers
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Reaction between volatile-bearing eclogite and harzburgite as a function of degree of interaction: Experimental constraints at 4 GPa Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Oded Elazar, Ronit Kessel
The mantle is known to be heterogeneous, mainly composed of peridotite and eclogite. Eclogite-derived hydrous melts may interact with harzburgite at the slab-mantle interface in subduction zones or in the sub-continental lithospheric mantle. In this study, such interactions were simulated by performing hybridization experiments in which a layer of eclogite was juxtaposed to a layer of harzburgite in
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Multiple magmatic processes revealed by distinct clinopyroxene populations in the magma plumbing system: A case study from a Miocene volcano in West Qinling, Central China Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Guo-Kun Zhang, Xiao-Wei Li, Ji-Feng Xu, Fang-Yue Wang, Thomas Bader, Guang-Yue Cao, Feng Huang, Xuan-Xue Mo, Wei Shan, Da-Peng Li, Guo-Chen Dong
The application of whole-rock compositions to trace magma evolution or crystal-melt equilibrium may be called into question when foreign crystals are incorporated into host magmas. To address this challenge, establishing the origins (orthocrysts, antecrysts, xenocrysts, etc.) of minerals with variable textures in magmatic plumbing systems is necessary. In this paper, we describe complex oscillatory
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Potassium isotope fractionation during silicate-carbonatite melt immiscibility and phlogopite fractional crystallization Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Ben-Xun Su, Qi-Qi Pan, Yang Bai, Wen-Jun Li, Meng-Meng Cui, Kwan-Nang Pang
Potassium (K) isotopes have been used as a tracer of K recycling in the Earth, but K isotope fractionation during magma evolution is poorly constrained. Here, we present K isotope data for a magmatic suite of alkaline silicate-carbonatite affinity. The suite was formed from liquid-liquid immiscibility and subsequent phlogopite fractionation. The K isotopic signatures of different rock types are in
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Yuchuanite-(Y), Y2(CO3)3·H2O, a new hydrous yttrium carbonate mineral from the Yushui Cu deposit, South China Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Wei Yao, Peng Liu, Guowu Li, Ningyue Sun, Wenqiang Yang, Chengyao Jiang, Wei Du, Chao Zhang, Wenlei Song, Nigel J. Cook, Jingwen Mao
A new mineral species, yuchuanite-(Y), ideally Y2(CO3)3·H2O, has been discovered and characterized in the Yushui Cu deposit in South China. The mineral occurs in bedded/massive ore and is associated with bornite, chalcopyrite, galena, sphalerite, bastnäsite-(Y), xenotime-(Y), anhydrite, and quartz. Individual crystals range in size from 30 to 300 μm. No twinning is observed. The mineral is colorless
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Nature and timing of Sn mineralization in southern Hunan, South China: Constraints from LA-ICP-MS cassiterite U-Pb geochronology and trace element composition Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 Tao Ren, Huan Li, Thomas J. Algeo, Musa Bala Girei, Jinghua Wu, Biao Liu
Accurately determining the timing and mechanism of metallogenesis of ore deposits is essential for developing a robust genetic model for their exploration. In this paper, we analyze the formation conditions of cassiterite in five major deposits of southern Hunan Province, one of the most important tungsten-tin (W-Sn) provinces in South China, using a combination of cathodoluminescence imaging, in situ
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The composition of mackinawite Am. Mineral. (IF 3.1) Pub Date : 2024-03-01 David Rickard
The composition of a mineral is a defining characteristic. The various compositions listed for mackinawite in current mineralogical databases and reference books, such as Fe(Ni)S and Fe1+xS, are both wrong and misleading. Statistical analyses of over 100 mackinawite compositions reported over the last 50 years show a mean composition of Me1.0S where Me = Fe + Co + Ni + Cu. Mackinawite is stoichiometric
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Comment on “Reexamination of the structure of opal-A: A combined study of synchrotron X-ray diffraction and pair distribution function analysis”—Concerning opal Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 B.H.W.S. de Jong
The paper by Lee et al. (2022) touches on various issues of amorphous silicas. In this comment, I shall discuss them, aiming at the metric of amorphous solids in structure property relationships. These were initiated in a pioneering study in 1874 by le Bell followed by van‘t Hoff (Ramberg 2017), who showed optical activity in organic systems to be a consequence of a postulated edge or face sharing
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American Mineralogist thanks the Reviewers for 2023 Am. Mineral. (IF 3.1) Pub Date : 2024-02-01
American Mineralogist relies on the volunteer efforts of researchers and scientists who participate and invest in the peer review process. The Journal reflects the hard work and time put in by many individuals. We genuinely thank the reviewers from the year 2023!Adam, J.Adcock, C.T.Ague, J.J.Ahmad, Q.Alwmark, CarlAnenburg, M.Angel, R.J.Antoine, C.Apen, F.Aranovich, L.Y.Artemyev, D.Arzilli, F.Asavin
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Crystal structure, hydrogen bonding, and high-pressure behavior of the hydroxide perovskite MgSi(OH)6: A phase relevant to deep subduction of hydrated oceanic crust Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Mark D. Welch, Jens Najorka, Bernd Wunder
The structural response to compression of the synthetic high-pressure hydroxide perovskite MgSi(OH)6, the so-called “3.65 Å phase,” has been determined to 8.4 GPa at room temperature using single-crystal XRD in the diamond-anvil cell. Two very similar structures have been determined in space groups P21 and P21/n, for which differences in oxygen donor-acceptor distances indicate that the non-centrosymmetric
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Raman spectroscopic investigation of selected natural uranyl sulfate minerals Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Tyler L. Spano, Travis A. Olds, Marshall McDonnell, Robert Smith, Ashley E. Shields
Uranyl sulfates are important constituents of uranium ores and represent a significant fraction of U(VI) minerals discovered in recent years owing to their propensity to form in mine tailings and legacy sites related to uranium exploration. Recently, we surveyed all published Raman spectra for uranium minerals and found significantly less easily accessible data available for uranyl sulfates relative
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Modified magnetite and hydrothermal apatite in banded iron-formations and implications for high-grade Fe mineralization during retrogressive metamorphism Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Kangxing Shi, Changming Wang, Leon Bagas, Hongyu Duan
Modified magnetite and hydrothermal apatite in banded iron formations (BIFs) are ideal minerals for studying hydrothermal and metamorphic processes and are applied to linking with high-grade Fe mineralization and metamorphism in iron deposits hosted by BIFs. In this study, we have investigated the geochemical composition of modified magnetite and hydrothermal apatite and in situ U-Pb geochronology
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Apatite trace element composition as an indicator of ore deposit types: A machine learning approach Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Kun-Feng Qiu, Tong Zhou, David Chew, Zhao-Liang Hou, Axel Müller, Hao-Cheng Yu, Robert G. Lee, Huan Chen, Jun Deng
The diverse suite of trace elements incorporated into apatite in ore-forming systems has important applications in petrogenesis studies of mineral deposits. Trace element variations in apatite can be used to distinguish between fertile and barren environments, and thus have potential as mineral exploration tools. Such classification approaches commonly employ two-variable scatterplots of apatite trace
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Crystal habit (tracht) of groundmass pyroxene crystals recorded magma ascent paths during the 2011 Shinmoedake eruption Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Shota H. Okumura, Mayumi Mujin, Akira Tsuchiyama, Akira Miyake
The morphologies and size distributions of groundmass crystals record conditions of magma ascent through volcanic conduits. However, morphological information (such as crystal shapes) has not been incorporated into crystal size distributions (CSDs). Here, we focused on the crystal habit, especially the shape variation due to the combination of (hk0) faces (hereafter “tracht”) of pyroxene microlites
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Reconstructing diagenetic mineral reactions from silicified horizons of the Paleoproterozoic Biwabik Iron Formation, Minnesota Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Samuel Duncanson, Latisha Brengman, Jena Johnson, Athena Eyster, John Fournelle, Aurélien Moy
Primary phases in iron-rich chemical sedimentary rocks are important archives of seawater geo-chemistry throughout the Precambrian. The record of seawater chemistry, however, is obscured by post-depositional changes that occur during diagenesis, metamorphism, and modern weathering. Recent studies have identified silica-cemented horizons in some Archean and Paleoproterozoic iron formation that may preserve
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On “Reexamination of the structure of opal-A: A combined study of synchrotron X-ray diffraction and pair distribution function analysis”—Reply to de Jong Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Seungyeol Lee, Huifang Xu, Hongwu Xu
We appreciate the interest from de Jong (2024, this issue) in our study on the structure of opal-A using synchrotron X-ray diffraction (XRD) and pair distribution function (PDF) analysis (Lee et al. 2022). Several comments were made by de Jong (2024) on the strengths and weaknesses of PDF analysis, the existence of 4- and 8-membered silica rings in the opal-A structure, and the usefulness of opal phase
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Crystal chemistry and thermodynamic properties of zircon structure-type materials Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Andrew C. Strzelecki, Xiaodong Zhao, Paul Estevenon, Hongwu Xu, Nicolas Dacheux, Rodney C. Ewing, Xiaofeng Guo
Zircon-class ternary oxide compounds have an ideal chemical formula of ATO4, where A is commonly a lanthanide and an actinide, with T = As, P, Si, or V. Their structure (I41/amd) accommodates a diverse chemistry on both A- and T-sites, giving rise to more than 17 mineral end-members of five different mineral groups, and in excess of 45 synthetic end-members. Because of their diverse chemical and physical
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Thermal and combined high-temperature and high-pressure behavior of a natural intermediate scapolite Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Paolo Lotti, G. Diego Gatta, Lara Gigli, Hannes Krüger, Volker Kahlenberg, Martin Meven, Davide Comboni, Sula Milani, Marco Merlini, Hanns-Peter Liermann
A natural intermediate member of the scapolite solid solution {Me47; chemical formula: (Na1.86Ca1.86K0.23Fe0.01)(Al4.36Si7.64)O24[Cl0.48(CO3)0.48(SO4)0.01]}, with the unusual I4/m space group, has been studied at various temperatures and combined high-T and high-P by means of in situ single-crystal and powder X-ray diffraction, using both conventional and synchrotron X-ray sources. In addition, single-crystal
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Equilibrium Sn isotope fractionation between aqueous Sn and Sn-bearing minerals: Constrained by first-principles calculations Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Mingguang Sun, Ryan Mathur, Caihong Gao, Yanjing Chen, Shunda Yuan
Equilibrium Sn isotope fractionation properties between aqueous Sn (2+, 4+) species and Sn-bearing minerals are the key to using tin isotopes to trace the transportation, enrichment, and precipitation of tin in various geological processes. However, the application of Sn isotope geochemistry has been impeded by the absence of equilibrium Sn isotopic fractionation factors between Sn-bearing minerals
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Identifying serpentine minerals by their chemical compositions with machine learning Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Shichao Ji, Fang Huang, Shaoze Wang, Priyantan Gupta, William Seyfried, Hejia Zhang, Xu Chu, Wentao Cao, J ZhangZhou
The three main serpentine minerals, chrysotile, lizardite, and antigorite, form in various geological settings and have different chemical compositions and rheological properties. The accurate identification of serpentine minerals is thus of fundamental importance to understanding global geochemical cycles and the tectonic evolution of serpentine-bearing rocks. However, it is challenging to distinguish
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Mannardite as the main vanadium-hosting mineral in black shale-hosted vanadium deposits, South China Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Lifei Yang, Zenghua Li, Yongpeng Ouyang, Teng Deng, Youguo Deng, Deru Xu
Black shale-hosted vanadium (V) deposits account for about 80% vanadium resources in the world, but only <2% vanadium in the black shale can be extracted mainly due to insufficient recognition on the occurrence mode of vanadium. It is commonly agreed that most vanadium in the black shale is hosted in clay minerals and organic matters, but it is not clear how the other parts of vanadium exist and whether
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Molybdenite-bearing vugs in microgranite in the Preissac pluton, Québec, Canada: Relicts of aqueous fluid pockets? Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Thomas Mulja, Anthony E. Williams-Jones
Field, petrochemical, and stable isotope data from peraluminous microgranite dikes and their molybdenite-bearing vugs in the Archean Preissac-Lacorne batholith, Québec, provide evidence for the transport and deposition of molybdenum by an aqueous fluid that exsolved from a felsic magma. A model is proposed in which the microgranite-forming liquid fractionated from a magma that was parental to and intruded
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The equilibrium boundary of the reaction Mg3Al2Si3O12 + 3CO2 = Al2SiO5 + 2SiO2 + 3MgCO3 at 3–6 GPa Am. Mineral. (IF 3.1) Pub Date : 2024-02-01 Yulia G. Vinogradova, Anton Shatskiy, Anton V. Arefiev, Konstantin D. Litasov
The stability of CO2 fluid in the Earth’s mantle is restricted by the carbonation of rock-forming minerals. Among those, the reaction with garnet is of particular interest because it constrains the stability of CO2 fluid in eclogites, whose minerals have been found in the CO2-bearing diamonds. In this work, we determined the equilibrium boundary for the reaction Mg3Al2Si3O12 (Prp) + 3CO2 (fluid) =
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Magmatic degassing controlled the metal budget of the Axi epithermal gold deposit, China Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Nuo Li, Bo Zhang, Thomas Ulrich, A.E. Williams-Jones, Yanjing Chen
From integrated textural and compositional studies of auriferous and barren pyrite/marcasite in the epithermal Axi gold deposit, China, we have identified a relationship between multiple gold mineralizing events, mafic magma recharge, and fluid-rock reactions. Three generations of pyrite (Py1–3) and four generations of marcasite (Mar1–4) record episodic gold mineralizing events, followed by silver
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Formation of mixed-layer sulfide-hydroxide minerals from the Tochilinite-Valleriite group during experimental serpentinization of olivine Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Thomas M. McCollom, Tori Hoehler, David A. Fike, Jennifer L. Houghton, Aaron Bell, Frieder Klein, Bruce Moskowitz, Peter Solheid
We report the formation of minerals from the tochilinite-valleriite group (TVG) during laboratory serpentinization experiments conducted at 300 and 328 °C. Minerals in the TVG are composed of a mixture of sulfide and hydroxide layers that can contain variable proportions of Fe, Mg, Cu, Ni, and other cations in both layers. Members of this group have been observed as accessory minerals in several serpentinites
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Correlation between Hinckley index and stacking order-disorder in kaolinite Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Wenxiu Rao, Xin Liu, Guocheng Lv, Meng Liu, Lijuan Wang, Jinan Niu, Zhaohui Li, Libing Liao
Hinckley index (Hi) can be used to characterize the crystallinity of kaolinite. Stacking order-disorder in kaolinite can considerably affect its crystallinity. However, the correlation between Hi and stacking order-disorder in kaolinite has not been reported thus far. Herein, the correlation between stacking order-disorder in kaolinite and Hi was investigated via experiments (XRD, IR spectroscopy,
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Enrichment of precious metals associated with chalcopyrite inclusions in sphalerite and pyrite Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 He Zhang, Gujie Qian, Fengfang Zhou, Yuanfeng Cai, Allan Pring
The results of investigations into enrichment of precious metals in sphalerite and pyrite from the Maluntou epithermal gold deposit, China, are reported. The obtained data suggest intimate associations of Au- and Ag-bearing nanoparticles with chalcopyrite inclusions in sphalerite and pyrite. The origins of chalcopyrite inclusions involved different hydrothermal processes, including recrystallization-driven
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Understanding the unique geochemical behavior of Sc in the interaction with clay minerals Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Yingchun Zhang, Xiandong Liu, Xiancai Lu, Rucheng Wang
Regolith-hosted rare earth elements (REEs) deposits received great attention due to the increasing incorporation of REEs in modern technologies. In lateritic Sc deposits and ion-adsorption deposits (IADs), Sc behaves quite differently from REEs: REEs adsorb as outer-sphere complexes on clay surface in IADs, while Sc could enter the lattice of clay minerals in lateritic Sc deposits. The unique behavior
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Crystal growth according to the law of proportionate effect Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 D.D. Eberl
This paper summarizes an approach to crystal growth that was published in parts in various articles over the course of 25 years by the present author and his colleagues. Evidence for this approach, which is confirmed in detail by data in the cited publications and in the figures and equations in the supplementary material that accompanies this paper (see the Online Materials1), comes mainly from the
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Structure and titanium distribution of feiite characterized using synchrotron single-crystal X-ray diffraction techniques Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Claire Zurkowski, Barbara Lavina, Kelsey Prissel, Stella Chariton, Vitali B. Prakapenka, Yingwei Fei
A solid solution of the mineral feiite (Fe3TiO5) was recently discovered in a shock-induced melt pocket of the Shergotty martian shergottite. It is particularly interesting for its potential as an indicator of pressure-temperature (P-T) and oxygen fugacity in martian crustal and mantle material. To date, complete crystallographic analysis of feiite has not been conducted, as the mineral was previously
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The search for a universal law of crystal growth: The law of proportionate effect? Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Daniel R. Hummer
Perhaps no mystery of the mineral kingdom has remained shrouded in the details of its chemistry and physics longer than that of their origin. Scholars have been fascinated by the formation of natural crystals since ancient times. Plato, who was so intrigued by the origin of crystal shapes that the five regular polyhedra now bear his name, speculated in ~360 BCE that “when earth is compressed by air
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Melt-mediated re-equilibration of zircon produced during meltdown of the Chernobyl reactor Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Denis Fougerouse, Thorsten Geisler, Steven M. Reddy, Matvei Aleshin, Laure Martin, Luc S. Doucet, Zakaria Quadir, David Saxey, William Rickard
The mineral zircon is used widely to constrain the age of rocks and the processes that formed them. Although zircon is robust to a range of physical and chemical processes, it may show evidence for rapid re-equilibration that is generally considered to reflect interaction with hydrous fluids. Here, we show that zircon grains that crystallized from melt produced during the catastrophic meltdown of the
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High-pressure behavior and structural transition of beryl-type johnkoivulaite, Cs(Be2B)Mg2Si6O18 Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 G. Diego Gatta, Martin Ende, Sofija Miloš, Nicola Rotiroti, Aaron C. Palke, Ronald Miletich
The beryl-group mineral johnkoivulaite, Cs(Be2B)Mg2Si6O18, was compressed hydrostatically in a diamond-anvil cell up to 10.2 GPa. In situ Raman spectroscopy and X-ray crystallography revealed a P6/mcc-to-P3c1 (second-order) phase transition on isothermal compression at the critical transition pressure Pc = 4.13 ± 0.07 GPa. The elastic parameters determined for the volume elasticity of the two polymorphs
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Melting and melt segregation processes controlling granitic melt composition Am. Mineral. (IF 3.1) Pub Date : 2024-01-02 Yang Yu, Xiao-Long Huang, Roberto F. Weinberg, Min Sun, Peng-Li He, Le Zhang
Several important processes in the petrogenesis of granite are still debated due to a poor understanding of complex interactions between minerals during the melting and melt segregation processes. To promote an improved understanding of the mineral-melt relationships, we present a systematic petrographic and geochemical analysis for melanosome and leucosome samples from the Triassic Jindong migmatite