The pyrite—marcasite relation | American Mineralogist
Abstract. The control of the precipitation of pyrite and marcasite by chemical environment suggests that these two minerals are not a dimorphous pair in the usual sense of the …
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Marcasite: Meaning, Properties, and Benefits You Should …
Pyrite-Marcasite: A powerful mix of the two crystals, Pyrite-Marcasite appears with orange, gold, and gray sections. Use this variety for manifestation. Calcite in Marcasite: This mix of Calcite and Marcasite creates a stunning stone with white and metallic gray structures. This variety is great for enhancing your connection with higher realms ...
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Replacement of pyrrhotite by pyrite and marcasite …
The pyrite crystals were >10 µm in size and randomly oriented. In comparison, marcasite crystals were <1 µm in size, and no significant overgrowth was observed. At pH 21°C <3, the marcasite nanocrystals showed the well-known crystallographic relationship with pyrrhotite, but at pH 21°C 3.96, the marcasite crystallites were randomly oriented.
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Marcasite vs Pyrite: Understanding the Key Differences
The answer is that both marcasite and pyrite are correct. However, marcasite specifically refers to the mineral iron sulfide, while pyrite is a broader term that can refer to a variety …
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Oxidation of Pyrite and Marcasite by Thiobacillus …
A comparison of the kinetic curves of marcasite and pyrite leaching shows that the rate of pyrite oxidation is greater (Table 1). The increase of the percent contribu-tion of pyrite from 1 to 3% resulted in a twofold decrease in the reaction rate, while the same increase in marcasite contribution - a threefold increase in the reaction rate.
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Electronic structure of 3d pyrite- and marcasite-type sulphides
Electronic structure calculations are reported for the 3d pyrite-type sulphides Fes2, CoS2, NiS2, CuS2 and ZnS2, and for marcasite-type FeS2. The energy bands are compared with the experimental data available. FeS2 is calculated to be a semiconductor, with an indirect gap of 0.7 eV (pyrite) or 0.4 eV (marcasite) separating filled t2g and empty eg sub …
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Comparisons of pyrite variability from selected western …
@article{osti_7128369, title = {Petrographic characterization of Kentucky coals. Final report. Part V. Pyrite size/form/microlithotype distribution in western Kentucky prepared coals and in channel samples from western Kentucky and western Pennsylvania}, author = {Frankle, K A and Hower, J C}, abstractNote = {Pyrite and marcasite distribution has been …
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Marcasite and Pyrite
Pyrite is also exceptionally dense, with a specific gravity of 5.0 to 5.2. Only hematite has a higher density. Marcasite tends to be lighter in color, and is sometimes referred to as "white iron pyrite". Sometime marcasite has a greenish tint, or a multi-colored tarnish that is the result of oxidation. But marcasite has an unstable orthorhombic ...
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Semiconductivity in pyrite, marcasite and arsenopyrite phases
DOI: 10.1016/0022-3697(65)90173-3 Corpus ID: 97832050; Semiconductivity in pyrite, marcasite and arsenopyrite phases @article{Hulliger1964SemiconductivityIP, title={Semiconductivity in pyrite, marcasite and arsenopyrite phases}, author={Fritz Hulliger and Etta Mooser}, journal={Journal of Physics and Chemistry of Solids}, …
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Marcasite
Pyrite and marcasite, on the other hand, have almost identical physical properties, making them tough to tell from each other. Let's go through their properties. Both are metallic and pale yellow to brassy yellow. Both can tarnish and be iridescent. Both are 6-6.5 on the Mohs' hardness scale. Neither have a particularly prominent cleavage ...
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Evaluating structure selection in the hydrothermal growth of …
In marcasite, we find that the spread of surface energies between the different facets is smaller than in pyrite, with the (010), (101), (110) and (111) facets all having low energies, in ...
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Marcasite
Marcasite, often mistaken for pyrite, exudes a vintage glamour and refined elegance, making it a beloved choice in jewelry design. Its brassy golden textures and intricate features draw both the curious eye and the spiritual heart, while the humble marcasite cruises under the radar in popular crystal healing practices, hiding powerful ...
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The mechanism and kinetics of the transformation from marcasite …
Pyrite and marcasite, the two polymorphs of FeS 2, are among the most abundant metal sulfides in the Earth's upper crust, and play key roles in the global cycles of Fe and S. Commonly, these two minerals form intergrowths or alternating concentric layers (Kullerud and Yoder 1959), and are found in many types of ore deposits, including …
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Reactions forming pyrite and marcasite from solution: II. Via …
DOI: 10.1016/0016-7037(91)90123-M Corpus ID: 96643251; Reactions forming pyrite and marcasite from solution: II. Via FeS precursors below 100°C @article{Schoonen1991ReactionsFP, title={Reactions forming …
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The distinction of pyrite from marcasite in nodular growths
page 181 note 3 M. J. Buerger (Amer. Min., 1931, vol. 16, p. 361) in his work on the structure of marcasite used molybdenum radiation. The indices and intensities of spots on marcasite photographs obtained in the present work using Cu-Kr radiation are in substantial agreement with his data.
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The mechanism and kinetics of the transformation …
Pyrite and marcasite, the two polymorphs of FeS 2, are among the most abundant metal sulfides in the Earth's upper crust, and play key roles in the global …
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Structural, optical and electrical impacts of marcasite …
In the mixture film, pyrite is surrounded by nanocrystalline marcasite. •. Marcasite has a bandgap of 0.85 to 0.88 eV, which is not as small as 0.4 eV. •. …
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Replacement of pyrrhotite by pyrite and marcasite under …
title = "Replacement of pyrrhotite by pyrite and marcasite under hydrothermal conditions up to 220 degrees C: An experimental study of reaction textures and mechanisms", author = "Gujie Qian and Fang Xia and Joel Brugger and William Skinner and Jiafang Bei and Guorong Cren and Allan Pring",
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Mineralization processes at the giant Jinding Zn–Pb deposit, …
The giant Jinding Zn–Pb deposit is in the Mesozoic–Cenozoic Lanping Basin of southern China and hosted by sandstone in the Early Cretaceous Jingxing Formation and limestone breccia and sandstone and gypsum in the Palaeocene Yunlong Formation. Mineral associations at the deposit are early (Stage 1) marcasite–sphalerite(–pyrite) …
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Marcasite
marcasite and pyrite crystal groups occur in the dolostone bedrock up and down in the Mississippi River in Wisconsin and Minnesota. These minerals, however, have been …
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Bonding Schemes for Compounds with the Pyrite, Marcasite…
DOI: 10.3891/ACTA.CHEM.SCAND.24-2993 Corpus ID: 98321367; Bonding Schemes for Compounds with the Pyrite, Marcasite, and Arsenopyrite Type Structures. @article{Brostigen1970BondingSF, title={Bonding Schemes for Compounds with the Pyrite, Marcasite, and Arsenopyrite Type Structures.}, author={Gunnar Brostigen and …
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Full article: Pyrite – the firestone
A summary of pyrite's main properties is given in. Table 1. Herein, pyrite refers to the cubic sulphide FeS 2; pyrites is used as the umbrella term for a collection of yellowish metallic sulphides, see. Table 2. Note that marcasite is pyrite's unstable low temperature dimorph. Marcasite is a pyrites, it is not pyrite.
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First-principle calculations of interaction of O2 with pyrite
DOI: 10.1016/S1003-6326(16)64141-9 Corpus ID: 138111176; First-principle calculations of interaction of O2 with pyrite, marcasite and pyrrhotite surfaces @article{Zhao2016FirstprincipleCO, title={First-principle calculations of interaction of O2 with pyrite, marcasite and pyrrhotite surfaces}, author={Cuihua Zhao and Jian-hua …
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Chemical composition аnd morphology of pyrite and marcasite …
Pyrite and marcasite aggregates were found in a sample of blue silty clay from an exploration drill core at the northern edge of the Troyanovo North mine, Maritsa East lignite basin, Bulgaria. The aggregates have various sizes – from 50 µm (single crystal twins) to 0.5 cm (large twinned aggregates). Pyrite occurs as single cubic and …
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The distinction of pyrite from marcasite in nodular …
More commonly the nodules exhibit small distorted octahedra which might easily be mistaken for marcasite. Indeed, in the past, many of these nodules from the …
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Kinetics of the marcasite-pyrite transformation: An infrared
Ansrn-lcr The kinetics of the solid-state transformation of marcasite to pyrite have been investigated using infrared spectroscopy. Kinetic analysis using the Johnson-Mehl or AvramiErofe'ev equation is based on measurements of infrared absorption intensity made on marcasite samples heated in the temperature range of 698-735 K. From the …
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Petrographic and chemical characteristics of pyrite-marcasite
Core recovered from Hess Rise contains concentrations of pyrite, marcasite, and barite in the lowermost meter of limestone (Unit II) and in the brecciated upper part of the underlying volcanic basement (Unit HI). Petrographic and chemical data indicate that the sulfide-barite assemblage in the limestone is mainly a product of low-temperature diagenetic processes.
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Pyrite
Pyrite (or iron pyrite) is the most common of the sulfide minerals.Chemically, it is known as iron disulfide (FeS 2).Its metallic luster and brassy hue have earned it the nickname fool's gold.Ironically, small quantities of actual gold are occasionally associated with pyrite. Its polymorphic form, called marcasite, has the same chemical formula but is structurally …
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Pyrite, pseudomorph after marcasite with pyrite and …
Specimen size: 14 x 10 x 6 inches. dc.description.abstract. Several large clusters of intergrown (former) marcasite crystals that have been replaced by pyrite--on pyrite, on sphalerite. This mineral specimen is from the Eagle mine, Gilman mining district, Eagle County, Colorado.
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Structural relationship between pyrite and marcasite
A comparison between HRTEM micrographs and images simulated for defect model structures indicates that the faults can be interpreted as single (101) layers of marcasite that disrupt the regular sequence of (002) layers in pyrite. Such a marcasite layer can be described as a boundary between two pyrite crystals that are related by a 2, screw ...
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