APS minerals are members of the alunite–jarosite family. The general formula of the APS minerals, the name has been coined based on the major elements in the supergroup, is AB 3 (XO 4) 2 (OH) 6, where A is a large cation (Na, U, K, Ag, NH 4, Pb, Ca, Ba, Sr, REE) in 12-fold coordination. B sites are occupied by cations of the elements …

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. This mineralogical zonation may be an exploration guide for mercury and uranium mineralization in the caldera complex environment.

Fluids in the pH 2–3 range can dissolve minerals such as volcanic glass, feldspar, and mica but not secondary kaolinite and alunite group minerals because Al is insoluble over these pH ranges ( et al., 1974; Sillitoe, 1993). All the above-mentioned research indicates that the kaolin deposits with associations rich in kaolin + …

The samples contain mainly quartz and clay, and minor amounts of alunite and jarosite. The clay fraction is composed of kaolinite and dickite and rarely illite and mixed-layered illite/smectite (I-S) (Fig. 6). The absence of feldspar minerals seems to be related to their being completely transformed to clays during hydrothermal alteration.

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 …

Accurate determination of clay minerals can be challenging due to the natural occurrence of interlayered phases, i.e., layers of different clay species such as illite and smectite. The overlap of peaks of the constituent minerals (e.g., illite and smectite), and the similarity of diffraction patterns when not treated with ethylene glycol, hampers …

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, …

kaolinite, from the Clay Minerals Society, Source Clays Repository, is a low-defect clay from Washington County, Georgia, USA, and was also ground and sieved to a size fraction of 45-125 µm. An Na-bearing alunite spectrum, formed at low temperatures and collected in Sadler, Texas, USA, is also used for comparison to CRISM spectra.

Uncommon micrometer-sized aluminium phosphates and sulphates of the alunite supergroup (APS minerals) associated with clay minerals were found in a …

Therefore, it is possible to study the dehydroxylation process of clays during thermal treatment.Chemical and mineralogical characterization of a kaolinitic clay (KN) …

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 …

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 …

Study of the dehydroxylation of kaolinite and alunite from a Mexican clay with DRIFTS-MS - Volume 51 Issue 1

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, …

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 …

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 …

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 …

FLOTATION OF ALUNITE AND CLAY MINERALS V. S. Uvarov andN. E. Vovk UDC 622.765 : 622.349.42 A difficulty encountered in the development of flotation schemes for extracting sulfate minerals is their sepa- ration from minerals with high solubility and high absorptivity. Such minerals include alunite, ferri-haUoysiteo and

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.

CLAY MINERALOGY AND CHEMISTRY OF HALLOYSITE AND ALUNITE DEPOSITS IN THE TURPLU AREA, BALIKESIR, TURKEY O¨ .IS I˙K ECE 1,2,* AND PAUL A. SCHROEDER 1 1 The University of Georgia, Department of Geology, Athens, GA 30602-2501, USA 2 Istanbul Technical University, Faculty of Mines, Department of Geological …

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 …

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.

Alunite is used as a representative mineral for indicating deposits in lithocaps, and lithocaps are generally related to the porphyry–(high-sulfidation) epithermal mineralization system. The study of alunite is of theoretical and exploration significance for prospecting potential underlying porphyry and epithermal deposits. Studies on alunite …

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 …

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.

alunite, a widespread rock-forming sulfate mineral that occupies pockets or seams in volcanic rocks such as rhyolites, trachytes, and andesites, …

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

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 …

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.