Peter J. Heaney

Peter J. Heaney
Pennsylvania State University | Penn State · Department of Geosciences

Ph.D. in Geosciences, Johns Hopkins, 1989

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198
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Publications

Publications (198)
Article
Full-text available
The coloration mechanism of Oregon sunstone is a classic and controversial topic in mineralogy because of the unique co-existence of anisotropic (green-red) and isotropic (red) color zones within single feldspar crystals. After nearly 50 years of research, no models proposed to date have satisfactorily accounted for all observed optical phenomena....
Article
Studies suggest that feitknechtite (β-MnOOH) is a prevalent, and perhaps necessary, intermediate phase during the synthesis of birnessite-like phases, the abiotic oxidation of Mn2+, and the transformation of biogenic hexagonal phyllomanganates to more complex Mn oxides in laboratory and natural systems. Researchers have generally described feitknec...
Article
The crystallization of hematite from precursor ferrihydrite was studied using time-resolved, angle-dispersive synchrotron X-ray diffraction in aqueous solutions at pH 10 and 11 and at temperatures ranging from 80 to 170 °C. Rietveld analyses revealed a non-classical crystallization pathway involving vacancy infilling by Fe as defective hematite nan...
Article
Iron (oxyhydr)oxides are sensitive indicators of pH, Eh, temperature, microbial activity, and climate conditions in the Critical Zone. The most ubiquitous and environmentally significant iron oxides in most soils are two-line ferrihydrite, goethite, and hematite. Here we present a comprehensive study of the transformation of two-line ferrihydrite t...
Article
In this study, we investigated an unusual natural Mn oxide hollandite-group mineral from the Kohare Mine, Iwate Prefecture, Japan, that has predominantly water molecules in the tunnels, with K, Na, Ca, and Ba. The specimens are labeled as type manjiroite, but our analyses show that Na is not the dominant tunnel species, nor is it even the primary t...
Article
Full-text available
Water can be stored in nominally anhydrous minerals as substitutional hydroxyl, generating vast but commonly unrecognized H2O reservoirs in ostensibly dry regimes. Researchers have long known that hematite (α-Fe2O3) can accommodate small concentrations of hydroxyl through the substitution of Fe3+ by 3H+. Our study of natural hematite has demonstrat...
Article
Full-text available
Raman spectra were collected for an extensive set of well-characterized layer-structure Mn oxide mineral species (phyllomanganates) employing a range of data collection conditions. We show that the application of various laser wavelengths, such as 785, 633, and 532 nm, at low power levels (30–500 μW) in conjunction with the comprehensive database o...
Article
Full-text available
Birnessite-like minerals are among the most common Mn oxides in surficial soils and sediments, and they mediate important environmental processes (e.g., biogeochemical cycles, heavy metal confinement) and have novel technological applications (e.g., water oxidation catalysis). Ca is the dominant interlayer cation in both biotic and abiotic birnessi...
Article
Full-text available
An expanded sedimentary section provides an opportunity to elucidate conditions in the nascent Chicxulub crater during the hours to millennia after the Cretaceous‐Paleogene (K‐Pg) boundary impact. The sediments were deposited by tsunami followed by seiche waves as energy in the crater declined, culminating in a thin hemipelagic marlstone unit that...
Article
Pyrite is a ubiquitous iron sulfide mineral that is oxidized by trace oxygen. The mineral has been largely absent from global sediments since the rise in oxygen concentration in Earth’s early atmosphere. We analyzed weathering in shale, the most common rock exposed at Earth’s surface, with chemical and microscopic analysis. By looking across scales...
Article
Microcrystalline calcite (micrite) dominates the sedimentary record of the aftermath of the Cretaceous–Paleogene (K–Pg) impact at 31 sites globally, with records ranging from the deep ocean to the Chicxulub impact crater, over intervals ranging from a few centimeters to more than seventeen meters. This micrite-rich layer provides important informat...
Article
Full-text available
Raman spectra were collected for an extensive set of well-characterized tunnel-structure Mn oxide mineral species employing a range of data collection conditions. Using various laser wavelengths, such as 785, 633, and 532 nm at low power levels (30-500 µW), as well as the comprehensive database of standard spectra presented here, it is generally po...
Article
With a focus on a large set of natural birnessites collected from terrestrial, freshwater systems, we applied and compared the capabilities of X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) to characterize crystal structure and che...
Article
Full-text available
Unlike most native metals, the unit cells of metal oxides tend to expand when crystallite sizes approach the nanoscale. Here we review different models that account for this behavior, and we present structural analyses for goethite (α-FeOOH) crystallites from ~10 to ~30 nm. The goethite was investigated during continuous particle growth via the hyd...
Article
The founding of the Mineralogical Society of America (MSA) in 1919 followed so closely on the heels of the discovery of X-ray diffraction (XRD) in 1912 that one might hypothesize a causal link. Was MSA born out of this scientific revolution? The formation of our Society conventionally is attributed to the desire for a professional journal and the n...
Article
Full-text available
High-temperature structural behavior of a stuffed derivative of α-quartz, Mg0.5AlSiO4, has been investigated using in situ synchrotron-based angle-dispersive powder X-ray diffraction (XRD) from 299 to 1273 K. Rietveld analysis of the XRD data indicates that the framework of Mg0.5AlSiO4 remains isostructural with α-quartz throughout the temperature...
Article
The society that led scientists through some of the most groundbreaking discoveries of the past century looks ahead to the next challenges with a Centennial symposium in late June.
Article
We have explored redox reactions between dissolved Cr and the phyllomanganate birnessite with high resolution through simultaneous synchrotron X-ray diffraction, X-ray spectroscopy, and fluid analysis at different concentrations of solution pH. Specifically, we collected time-resolved synchrotron X-ray diffraction patterns and X-ray absorption near...
Article
Synchrotron X-ray diffraction was used to monitor the hydrothermal precipitation of akaganeite ( β -FeOOH) and its transformation to hematite (Fe 2 O 3 ) in situ . Akaganeite was the first phase to form and hematite was the final phase in our experiments with temperatures between 150 and 200 °C. Akaganeite was the only phase that formed at 100 °C....
Article
The authors investigated "rainbow" hematite from Minas Gerais, Brazil, using electron microscopy, atomic force microscopy, and synchrotron X-ray diffraction to determine the cause of its intense wide-angle iridescence. The study revealed that the interference is produced by a highly periodic microstructure consisting of spindle-shaped hematite nano...
Article
Because of their nanocrystallinity and high cation exchange capacities, birnessite phases can control the cycling of heavy metals in soils and groundwaters, and they also are implicated in the oxidation of transition metals in natural environments. Birnessite reactivity is determined by crystal structure and composition. Because birnessites typical...
Article
We used time-resolved synchrotron X-ray diffraction to follow the complete dissolution of synthetic triclinic Na-birnessite as promoted by the trihydroxamate siderophore desferrioxamine B (DFOB). Many microorganisms employ siderophores to increase the availability of Fe, Mn, and other trace metals for metabolic processes. Our primary goal was to qu...
Article
Iris quartz specimens from geodes in the Deccan Trap basalts of west-central India have been described since 1860. These quartz crystals exhibit dominant terminal faces, and iridescence is visible on only the minor z {011} faces and not the major r {101} faces. For this study, we analyzed iris quartz crystals from India's Jalgaon District using sca...
Article
The characterization of birnessite structures is particularly challenging for poorly crystalline materials of biogenic origin, and a determination of the relative concentrations of triclinic and hexagonal birnessite in a mixed assemblage has typically required synchrotron-based spectroscopy and diffraction approaches. In this study, Fourier-transfo...
Article
The nucleation and growth of akaganeite and its transformation to hematite under hydrothermal conditions were monitored over a temperature range of 80 to 200 °C using time-resolved synchrotron X-ray diffraction. In each experiment, akaganeite was the first phase to form and hematite was the final phase. No intermediate phases were identified. The i...
Article
div class="title">EPMA WDS Peak Position Analysis of Mineral Chemistry in Fossils - Volume 22 Issue S3 - Douglas C. Meier, Kimberly K. Foecke, Edward P. Vicenzi, Peter J. Heaney, Russell Graham
Article
Carbonado is a porous polycrystalline diamond rock found in central African and Brazilian placer deposits. It contains unsupported radiogenic isotopes of He, Ne, Kr, Xe, and Pb. Here we show that these, and the radiation-related defects introduced to the diamond structure, are a result of uranium precipitation, with no isotopic or spectroscopic evi...
Article
Charles Darwin analogized the diversification of species to a Tree of Life. This metaphor aligns precisely with the taxonomic system that Linnaeus developed a century earlier to classify living species, because an underlying mechanism - natural selection - has driven the evolution of new organisms over vast timescales. On the other hand, the effort...
Article
Mr. President, Honorees, Members of MSA: Twenty years ago, our Society confronted an array of challenges. The severity of the situation can best be described by reference to that illustrious American philosopher, Donald Rumsfeld. We faced the “known knowns”—the challenges we knew we knew. These included a plunge in membership from a high of 2900...
Article
Synchrotron powder X-ray diffraction and scanning electron microscopy examinations of manganese oxide concretions/nodules (~0.3–1.0 mm diameter) from ODP Site 1262 on Walvis Ridge in the Southeastern Atlantic Ocean revealed that they consist primarily of the layered Mn oxide phase jianshuiite [(Mg,Mn,Ca)Mn34+O7·3H2O]. The nodules are from an interv...
Article
Hydrous manganese oxides are an important class of minerals that help regulate the geochemical redox cycle in near-surface environments and are also considered to be promising catalysts for energy applications such as the oxidation of water. A complete characterization of these minerals is required to better understand their catalytic and redox act...
Conference Paper
Here we present a novel method for simultaneous measurement of the birnessite structure and the extent of Cr oxidation at different solution pH conditions. We collected time-resolved synchrotron X-ray diffraction (TR-XRD) patterns of birnessite every 15s while passing 1 mM Cr(III) nitrate solutions through a capillary cell, and we quantified Cr(VI)...
Conference Paper
A specular, metamorphic hematite from the Andrade Mine in João Monlevade, Minas Gerais, Brazil, is highly iridescent and thus frequently marketed as “rainbow hematite”. In an online report (http://minerals.gps.caltech.edu/), Rossman and Ma presented field-emission scanning electron micrographs (FESEM) of rainbow hematite from Brazil and other local...
Article
Laboratory experiments that explore the bioprecipitation or redox transformations of layered Mn oxides commonly employ buffers, such as the HEPES and MES buffers, to maintain solution pH to near neutrality. The assumption is that holding solution pH constant does not serve as the primary control for the variety of Mn oxide produced. To test this as...
Article
A structural derivative of quartz with the composition Mg0.5AlSiO4 has been grown from glass and characterized using synchrotron X-ray diffraction (XRD), transmission electron microscopy (TEM), and 29Si nuclear magnetic resonance (NMR) spectroscopy. Rietveld analysis of the XRD data indicates that the framework of Mg0.5AlSiO4 is isostructural with...
Article
The development of time-resolved, synchrotron scattering techniques has recently enabled the collection of in situ mineral abundance data during mineral-fluid reactions. However, few computational algorithms exist to analyze the kinetics of such reactions. Here we present MinKin (for “Mineral Kinetics”), a global optimization code for Matlab capabl...
Article
In ferruginous soils, nano- to microscale hematite (α-Fe2O3) plays a central role in redox processes and contaminant cycling. Hematite is known to incorporate structural OH− and water, and the requisite charge balance is achieved by iron vacancies. Prior researchers have suggested that the defective hematite structures form unique phases called “pr...
Article
Full-text available
Nanominerals are characterized by crystal dimensions that fall between 100 and 1 nm, and as the length scale of atomic ordering approaches the lower end of this range, a material’s physical and chemical properties may dramatically diverge from what is observed at the macroscale. Indeed, when atomic correlation lengths approximate the dimensions of...
Article
Time-resolved synchrotron X-ray powder diffraction data were used to investigate the dehydration behavior of the chalcophanite (ZnMn3O7·3H2O) structure from 300 to 1060 K. Rietveld refinements revealed two obvious phase changes, at ~450 and ~950 K, corresponding to the dehydration of chalcophanite followed by transformation to a spinel structure (M...
Article
Models of 1, 2, and 3 nm diameter anatase and rutile particles, with either a surface monolayer of water or a single water molecule at different surface sites, were subjected to energy minimizations using density functional theory (DFT). The optimized structures show that H2O molecules bind covalently to both anatase and rutile particles via underc...
Chapter
On the Earth’s surface, quartz (or, more properly, alpha-quartz) is by far the most common of the crystalline forms of silicon dioxide (SiO2), constituting 12 % of the crust by volume. Among the igneous rocks, quartz is abundant within granites, granodiorites, pegmatites, and rhyolites. The weathering and erosion of these rocks tend to concentrate...
Article
To measure the uptake of radioactive Cs in soils that are rich in Mn oxides, we applied time-resolved synchrotron X-ray diffraction (TR-XRD), inductively coupled plasma-mass spectrometry (ICP-MS), and analytical scanning electron microscopy (SEM) to determine the kinetics and mechanisms of aqueous Cs substitution in the phyllomanganate hexagonal H-...
Article
Full-text available
Birnessite and other charged layered manganese oxide minerals exhibit interlayers with variable cation-water behavior that controls many environmentally important cation exchange, adsorption, and redox processes. The occurrence of birnessite phases as fine-grained materials with corresponding high-surface areas makes them effective in controlling s...
Article
We have monitored the homogeneous crystallization of TiO2 phases from aqueous TiCl4 solutions at 100 °C using both time-resolved small-angle X-ray scattering (TR-SAXS) and time-resolved wide-angle X-ray scattering (TR-WAXS). The WAXS data revealed that metastable anatase was the first phase to crystallize, but it began transforming to rutile within...
Article
In this study, we applied time-resolved synchrotron X-ray diffraction (TRXRD) to develop kinetic models that test a pro-posed two-stage reaction pathway for cation exchange in birnessite. These represent the first rate equations calculated for cat-ion exchange in layered manganates. Our previous work has shown that the substitution of K, Cs, and Ba...
Article
A non-metallic flow-through reaction cell is described, designed for in situ time-resolved X-ray diffraction coupled with stable isotope analysis. The experimental setup allows the correlation of Cu isotope fractionation with changes in crystal structure during copper sulfide dissolution. This flow-through cell can be applied to many classes of flu...
Article
The positions of hydrogen (deuterium) cations within the interlayer of synthetic Na- and K-birnessite samples have been determined for the first time using Rietveld analysis and Fourier difference syntheses, from time-of-flight powder neutron diffraction data. This study revealed that two symmetry-related D(H) positions are located ~1 Å above and b...
Article
Pietersite has been described as a brecciated variety of tiger's-eye. This study examined pietersite specimens from Namibia and China (the main sources) using powder X-ray diffraction, optical microscopy, environmental scanning electron microscopy, and conventional gemological methods. On the basis of the results, quantitative approaches were devel...
Article
Located in the uplands of the Valley and Ridge physiographic province of Pennsylvania, the Susquehanna/Shale Hills Critical Zone Observatory (SSHO) is a tectonically quiescent, first-order catchment developed on shales of the Silurian Rose Hill Formation. We used soil cores augered at the highest point of the watershed and along a subsurface water...
Article
The removal of Mn(II) from coal mine drainage (CMD) by chemical addition/active treatment can significantly increase treatment costs. Passive treatment for Mn removal involves promotion of biological oxidative precipitation of manganese oxides (MnOx). Manganese(II) removal was studied in three passive treatment systems in western Pennsylvania that...
Article
The metatorbernite [Cu(UO2)2(PO4) 2·8H2O] structure comprises autunite-type sheets of corner-sharing uranyl square bipyramids and phosphate tetrahedra, with the interlayer region occupied by Cu2+ ions and molecular water. Previous studies have shown that heating induces stepwise dehydration and reduction in basal spacing. Structures ofthe lower hyd...
Article
We have explored the exchange of Cs for interlayer Na in birnessite using several techniques, including transmission electron microscopy (TEM) and time-resolved synchrotron X-ray diffraction (XRD). Our goal was to test which of two possible exchange mechanisms is operative during the reaction: (1) diffusion of cations in and out of the interlayer o...
Article
We have monitored the hydrothermal crystallization of titania nanoparticles by in situ X-ray diffraction (XRD). Using the refined average structures from the XRD measurements, we calculated potential energy variations with particle size on periodic bulk structures using density functional theory (DFT). These variations cannot account for the enthal...
Article
Fine-grained titanium oxide minerals are important in soils, where they affect a variety of geochemical processes. They are also industrially important as catalysts, pigments, food additives, and dielectrics. Recent research has indicated an apparent reversal of thermodynamic stability between TiO2 phases at the nanoscale thought to be caused by an...
Article
Full-text available
Here we report the first continuous time-resolved X-ray diffraction analysis of a biologically mediated mineral reaction. We incubated total membrane (TM) fractions of the facultative anaerobe Shewanella oneidensis in an anoxic environmental reaction cell with formate (as electron donor via formate dehydrogenase) and powdered birnessite, a layered...
Article
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Corrections are made to two equations and one table value in “Thermal expansion of anatase and rutile between 300 and 575 K using synchrotron powder X-ray diffraction” [Powder Diffr. 22, 352–357 (2007)].
Article
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Rietveld refinements using synchrotron powder X-ray diffraction data were used to study the crystal structure and dehydration behavior of pure monoclinic palygorskite samples from Korea and Alaska. The 300 and 100 K palygorskite structures in air compare well with previous models but provide additional details about zeolitic H2O sites and reveal th...
Article
Rietveld refinement using synchrotron powder X-ray diffraction data of the ranciéite, Ca0.19K0.01(Mn4+0.91◻0.09)O2⋅0.63H2O, crystal structure reveals significant differences from that reported previously. The interlayer H2O molecules occupy sites halfway between the Mn,O octahedral sheets. The Mn sites in the octahedral sheets have 10% vacancies, a...
Article
Full-text available
Advances in the design of environmental reaction cells and in the collection of X-ray diffraction data are transforming our ability to study mineral-fluid interactions. The resulting increase in time resolution now allows for the determination of rate laws for mineral reactions that are coupled to atomic-scale changes in crystal structure. Here we...
Article
Sixty-seven natural blue diamonds, including the two largestsuch gemstones known (the Hope and the Blue Heart), were probedby ultraviolet radiation, and their luminescence was analyzedusing a novel spectrometer system. Prior to this study, thefiery red phosphorescence of the Hope Diamond was regarded asquite rare compared to greenish-blue phosphore...
Article
Full-text available
High-precision unit-cell parameters for the TiO2 polymorphs anatase and rutile at temperatures between 300 and 575 K have been determined using Rietveld analysis of synchrotron powder XRD data. Polynomial models were used to express the tetragonal unit-cell parameters as a function of absolute temperature, with a (anatase)=1.759 37×10−8×T2+6.418 1...
Article
Full-text available
Numerous natural-color colored diamonds from the Aurora Butterfly of Peace and other collections were studied using a new type of fluorescence spectrometer that has many advantages for gemological research, including high portability, low cost, and rapid collection times. For comparison, 10 irradiated diamonds were also studied. With only two excep...