Minerals | Free Full-Text | Hydrothermal Alteration …
Common products of the interaction between the kind of fluids mentioned previously and andesitic rocks include sulfate minerals, clay minerals (e.g., smectites and chlorite), quartz, pyrite, and iron …
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Study of the dehydroxylation of kaolinite and alunite from a …
Study of the dehydroxylation of kaolinite and alunite from a Mexican clay with DRIFTS-MS - Volume 51 Issue 1
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The Origin of High-Alumina Clay Minerals—A Review
High-alumina minerals refer, in this paper, to Al-rich, normal sedimentary phases, including gibbsite, boehmite, diaspore, possibly "proto-diaspore" and "proto-alunite", "Al-chlorite", and corundum, in association with kaolin minerals. They may be derived from any common Al-containing rock. Processes of origin include direct bauxitization of non-clay silicate …
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Alunite
The ROC curve in (Fig. 8.17) indicates a significant difference in the discriminated between bearing-altered minerals, kaolinite, alunite, calcite and dolomite, granite, ... In terms of ROC area, the clay, quartz, and carbonate have an area difference of 92%, 83%, and 85%, respectively (Fig. 8.17), which confirms the Mahalanobis algorithm.
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Progressive formation of halloysite from the hydrothermal
Occurrences of halloysite-rich material in altered volcanic rocks, principally trachyandesites, dacites, and tuffs, extend over an area of ∼1 km2 in the southwestern part of Limnos, Island, northeast Aegean Sea, Greece. The present study was designed to investigate the alteration processes which acted on the biotite in these volcanic rocks, to …
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Mineralogical and Geochemical Characteristics and Genesis …
Ece, and Schroeder, P.A., 2007 Clay mineralogy and chemistry of halloysite and alunite deposits in the Turplu area, Balikesir, Turkey Clays and Clay Minerals 55 18 – 35. CrossRef Google Scholar Ece, Ö İ İ Schroeder, P.A. Smilley, M. and Wampler, M., 2008 Acid-sulfate alteration volcanic rocks and genesis of halloysite and alunite ...
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Isotope geochemistry and origin of illite-smectite and …
Mineralogical and Geochemical Characteristics and Genesis of the Gülzelyurt Alunite-Bearing Kaolinite Deposit Within the Late Miocene Gödeles Ignimbrite, Central Anatolia, Turkey. Clays and Clay Minerals, Vol. 62, Issue. 6, p. 477. CrossRef; Google Scholar; Yuan, Ye Shi, Guanghai Yang, Mengchu Wu, Yinuo Zhang, Zhaochong Huang, …
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Thermal treatment of kaolin: the effect of mineralogy on the …
The determination of alunite is based on the SO 3 content of the samples, since there is no other detectable mineral which may contain S. The K 2 O content, after extracting the K 2 O in alunite, is used for the determination of illite since there is no other K-containing mineral detected in the samples. The average content of K 2 O in illite and …
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Rare aluminium phosphates and sulphates (APS) and clay mineral
Uncommon micrometer-sized aluminium phosphates and sulphates of the alunite supergroup (APS minerals) associated with clay minerals were found in a polymictic Permian granite hosted hydrothermal breccia in the Velence Mts. (Hungary). The mineral assemblage was studied with TEM, XRD, EMPA and FTIR with the aim of …
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Differentiating Styles of Alteration within Kaolin-Alunite
The Biga Peninsula of NW Turkey is host to many kaolin and halloysite deposits with mineralization occurring at the intersections of fault zones in contact with Late Eocene.Miocene calc-alkaline volcanic rocks. Distinguishing between the relative over of hypogene by supergene processes in these deposits is a challenge and …
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(PDF) DIFFERENTIATING STYLES OF ALTERATION WITHIN KAOLIN-ALUNITE
Minerals identified include quartz (Q), kaolinite (K), and alunite (A). Patterns are representative of (1) Silicified zone. SA2-30 is along the fault and it is a-quartz-rich; (2) Kaolinite-rich zone.
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CLAY MINERALOGY AND CHEMISTRY OF HALLOYSITE AND ALUNITE DEPOSITS IN …
The mineral assemblage along fault zones is dominated by halloysite and sometimes alunite. The alunite is nearly end-member in composition (a = 6.995 Å, c = 17.195 Å ) often occurring with a minor Ca phosphate phase. Of the two deposits studied, the more northerly mine contains more alunite relative to halloysite.
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Detection of Interlayered Illite/Smectite Clay Minerals with …
The occurrence of zeolite and an outcrop of bentonite rocks was described by Arribas et al. [] and García-Romero et al. [].A description of the mineral assemblage of the Rodalquilar area was presented by Arribas et al. [].The surface rocks are characterized by quartz, k feldspar, illite, smectite, alunite, pyrophyllite and several Fe oxides such as …
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Alunite KAl3(SO4 2(OH)6
Alunite KAl3(SO4)2(OH)6 c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Hexagonal. Point Group: 32/m or 3m. Crystals typically pseudocubic {0112} or tabular …
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(PDF) Alunite characterization in the upper Eocene clay …
Therefore, the preliminary approach of the El Gnater In this phase, smectite clay minerals of the Late Eocene, alunite genesis mode can be the following one (Fig. 8): rich with aluminium, potassium, calcium and sodium 123 Author's personal copy Carbonates Evaporites change progressively to alunite under the action of the The Sciences Faculty …
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Acid-sulphate hydrothermal alteration of andesitic tuffs and …
Ece, Ö.I. & Schroeder, P.A. (2007) Clay mineralogy and chemistry of the halloysite and alunite deposits in the Turplu area, Balıkesir, Turkey. Clays and Clay Minerals, 55, 18 – 36 . CrossRef Google Scholar
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Rare aluminium phosphates and sulphates (APS) and …
Uncommon micrometer-sized aluminium phosphates and sulphates of the alunite supergroup (APS minerals) associated with clay minerals were found in a …
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The geology of aluminium phosphates and sulphates of the alunite …
Sulphuric waters, when exposed to clay-rich sediments converted clay minerals to alunite and natroalunite. Smectitic clay was converted into hydrated halloysite by interaction with H 2 SO 4 (reaction (1)). Karstification and the formation of APS mineralization was a single-phase process that obviously took place at higher …
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Clay mineralogy and chemistry of halloysite and alunite deposits in …
A field-mapping and crystal-chemical study of two alunite- and halloysite-rich deposits in the Turplu area, situated northwest of Balıkesir on the Biga Peninsula of northwest Turkey reveals a mineralogically diverse and a potentially economic clay deposit. The mineral assemblage along fault zones is dominated by halloysite and sometimes …
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Mineralogical and geochemical constraints on the …
The main hydrothermal alteration is advanced argillic, characterized by massive vuggy quartz, clay minerals mainly kaolinite, and sporadic alunite supergroup minerals. Mineralization is closely associated with silicic and phyllic alteration types, along with …
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Alunite KAl3(SO4 2(OH)6
Alunite KAl3(SO4)2(OH)6 c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Hexagonal. Point Group: 32/m or 3m. Crystals typically pseudocubic {0112} or tabular {0001} with flat vicinal rhombohedra, to 1 cm; fibrous to columnar, porcelaneous, commonly granular to dense massive. Physical Properties: Cleavage: On {0001}, perfect ...
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Rare aluminium phosphates and sulphates (APS) and …
Uncommon micrometer-sized aluminium phosphates and sulphates of the alunite supergroup (APS minerals) associated with clay minerals were found in a polymictic Permian granite hosted hydrothermal breccia in the Velence Mts. (Hungary). The mineral assemblage was studied with TEM, XRD, EMPA and FTIR with the aim of revealing the …
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Alunite
K-bearing alteration minerals (e.g., amphibole, biotite, adularia, muscovite, alunite, illite, and various other clay minerals) are almost ubiquitously associated not only with porphyry system mineralization and with low sulfidation epithermal deposits, but also with other types of mineralization (orogenic gold, Carlin-type, VHMS) and therefore ...
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The Gümüşköy (Kütahya, Turkey) kaolin deposit and its …
The Gümüşköy kaolin clay deposit, located ~40 km northwest of Kütahya, Turkey, has promising reserves for ceramic production. In order to evaluate the potential use of this region, five representative clay samples were collected and characterized with X-ray diffraction, polarized light optical microscopy, X-ray fluorescence spectrometry, …
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Halloysite clay minerals – a review | Semantic Scholar
Abstract Halloysite clay minerals are ubiquitous in soils and weathered rocks where they occur in a variety of particle shapes and hydration states. Diversity also characterizes their chemical composition, cation exchange capacity and potassium selectivity. This review summarizes the extensive but scattered literature on halloysite, from its natural …
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Alunite supergroup minerals from advanced argillic …
The study of alunite supergroup minerals (alunite, jarosite, and aluminum-phosphate-sulfate (APS) minerals) that are part of the acidic alteration assemblages, can help to better constrain the hydrothermal and supergene alteration events, as these minerals record information about the precipitation environment and the nature and …
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Alunite | Mineral, Description, Uses, & Facts | Britannica
alunite, a widespread rock-forming sulfate mineral that occupies pockets or seams in volcanic rocks such as rhyolites, trachytes, and andesites, …
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Zeolite-clay mineral zonation of volcaniclastic sediments …
This zone then grades vertically and laterally into fresh glass. The clay minerals are a dioctahedral smectite, a mixed-layer clay mineral, and a 7-A clay mineral. The mixed-layer and 7-A clay minerals are associated with the potassium feldspar-alunite zone of alteration, and the dioctahedral smectite is associated with clinoptilolite.
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Compositional and Structural Variations in the Size
Hurst, V. J., ed. (1979) Field Conference on Kaolin, Bauxite and Fuller's Earth: Clay Minerals Society Annual Meeting, Macon, Georgia, 1979, 107 pp. Keller, W. D. (1977) Scan electron micrographs of kaolins collected from diverse environments of origin—IV. Georgia kaolin and kaolinizing source rocks: Clays & Clay Minerals 25, 311–345.
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Stable isotope geochemistry of clay minerals | Clay Minerals
Stable isotope geochemistry of clay minerals - Volume 31 Issue 1. The equilibrium H-isotope fractionation factors vs. 10 6 × T −2 for kaolinite and probably smectite and illite are monotonic curves between 350-0°C. More complex curves, with a minimum fractionation near 200°C, are probably influenced by surface effects and/or disequilibrium …
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