Rather Than the Chlorite Group (14A Or 2:1 Layer Gested by Albee (1962), to Continue the Use of Plus an Interlayer Sheet)

Total Page:16

File Type:pdf, Size:1020Kb

Rather Than the Chlorite Group (14A Or 2:1 Layer Gested by Albee (1962), to Continue the Use of Plus an Interlayer Sheet) Canadian Mineralogist Vol. 13, pp. 178-180 (1975) NOMENCLATURE OF THE TRIOCTAHEDRAL CHLORITES PETER BAYLISS Mineralogisch-Kristallographisches Institut der Universitiit Gbttingen, West Germany* Abstract proximate chemical composition of a trioctahe Trioctahedral mineral species within the chlo dral chlorite, one must use cell constants or re rite group have the end-member compositions as flection intensities rather than simple compari follows: clinochlore (MgsAl)(Si3Al)O,0(OH)8, cha- son. For example, the curves of Shirozu (1958) mosite (Fe.,+ +Al)(Si3Al)O,0(OH)8, nimite (NisAl) relate the (001) spacing to the MgVISilv^±AlVIAl,v (Si3Al)O10(OH)8, and pennantite (Mn,Al)6(Si,Al)4O10 substitution, and the 6-axis length to the Mg^± (OH)8. The varietal names of brunsvigite, corundo- Fe++ substitution. Also, the intensity ratio of philite, daphnite, delessite, diabantite, grovesite, (002 + 004)/(003) reflections has been related kammererite, kotchubeite, leuchtenbergite, ortho- to Mg^±Fe++ substitution by Petruk (1964). The chamosite, pennine, pseudothuringite, pycnochlo- accuracy of these methods is discussed by Bai rite, ripidolite, sheridanite, talc-chlorite and thurin- gite should be discarded. The varieties between ley (1972). In addition, Brown & Bailey (1962) these end-member compositions should be de recognized four different one-layer poly-types scribed by chemical element adjectives. At present (lib, lb orthorhombic, lb monoclinic, and la), the polytype symbols of Brown & Bailey (Amer. which cut across all the arbitrary nomenclature Mineral. 47, 819) should be used. divisions established for different compositions. Therefore the nomenclature needs re-evaluation Introduction and simplification. Compilations and classifications of the tri octahedral chlorites have been made by Orcel Discussion et al. (1950), Serdyuchenko (1953), Hey (1954), Both Foster (1962) and Brown & Bailey (1962) Brindley & Gillery (1956), Lapham (1958), Fos have plotted a diagram from numerous natural ter (1962), Phillips (1964), Strunz (1970), and samples to indicate the extent of substitution Fleischer (1971). Problems have arisen because with respect to Mg^±Fe and (Mg, Fe)VISiIv^± different names have been given in the original A1VIA1IV in the chlorite group. The number of descriptions for similar compositions, and then samples recorded that are either manganese- or the same name has been used for different com nickel-rich is limited. Therefore it appears un positional ranges in various classifications. Each necessary to give tabulated compilations or com of these classifications is based upon different positional diagrams in this paper. arbitrary divisions within a complex solid-solu Initially the chlorite series was described with tion series. Some authors avoid nomenclature serpentine Mg3Si2Os(OH)4, and amesite (Mg*Al) problems by the use of the group name chlorite (SiAl)Os(OH)4 as the end-members, but later instead of a species name, which is also undesir both of these minerals were found to belong to able as there are a number of valid species. the kaolinite-serpentine group (7A or 1:1 layer) There seems to be no adequate reason, as sug rather than the chlorite group (14A or 2:1 layer gested by Albee (1962), to continue the use of plus an interlayer sheet). In order to fit together a large number of ill-defined varietal names, es the tetrahedral and octahedral sheets in chlorite pecially as only the end-member compositions to produce a stable structure, some Al substitu are accepted as species by the Commission on tion is essential to produce tetrahedral and octa New Minerals and Mineral Names, Internation hedral sheets of similar a- and Z>-axis dimensions. al Mineralogical Association. This limits the composition to approximately the The powder diffraction data of trioctahedral center of this series. This composition of (MgsAl) chlorites are similar, as shown by a comparison (Si3Al)Oio(OH)8 is most commonly used to de of data in Selected Powder Diffraction Data for scribe the mineral species clinochlore. The te Minerals (1974). Therefore, to ascertain the ap- trahedral composition of (Si3Al) has been used for the end-member, as it represents the mid point of the series and is fairly simple, although *On leave from Department of Geology, Univer the average tetrahedral composition of natural sity of Calgary, Alberta T2N 1N4 samples is near (Su.tAIi.s). A common type of 178 Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/2/178/3445639/178.pdf by guest on 28 September 2021 nomenclature of the trioctahedral chlorites 179 substitution in clinochlore is MgVISirvr^±AlvlAlIv. chromium is very large compared to aluminium Varietal names that should be discarded include (Burns 1970), which means that chromium leuchtenbergite which is a clinochlore, pennine strongly prefers octahedral sites. Therefore until (often misspelled as penninite) which is a mag- conclusive evidence is presented for tetrahedral nesian siliconian clinochlore, and sheridanite chromium, it should be taken to occur only in which is an aluminian clinochlore. The varietal octahedral sites. name of talc-chlorite with a composition similar The endrmember composition of (NisAl)(Si3« to serpentine should be discarded because it Al)Oio(OH)8 is produced by complete substitu falls considerably outside the compositional tion of magnesium in clinochlore by nickel. A range of the trioctahedral chlorite group. nickel-rich trioctahedral chlorite has been de Complete substitution of magnesium by fer scribed by De Waal (1970) with the name of rous iron in clinochlore produces the end-mem nimite. ber composition (Fe5++Al)(Si3Al)Oi0(OH)8. For Complete substitution of magnesium in clino this composition, chamosite appears to be the chlore by manganese produces the end-member most logical name as it is the most often used (Mn,Al)6(Si,Al)«Oio(OH)8. The first occurrence name in the literature for approximately this of this manganese-rich trioctahedral chlorite was composition. The substitution of Fe++Si by described by Smith et al. (1946), who called it A1V,A1IV is frequent; the reverse substitution is pennantite. Initially grovesite was described by rare, although it frequently occurs in clino Bannister et al. (1955) as a member of the kao- chlore. In some chamosites, ferric iron results linite-serpentine group, but later it was decided from oxidation of ferrous iron with a loss of by Peacor et al. (1974) to be a one-layer poly hydrogen, but Foster (1962) considers ferric iron type Mn trioctahedral chlorite, whereas pennan as a normal constituent unless there is other tite is a two-layer polytype Mn trioctahedral evidence of secondary oxidation. The classifica chlorite. Because a polytype has only varietal tion of Hey (1954) into orthochlorites (unoxi- status, the name of grovesite should be dis dized ferrous) and leptochlorites (oxidized fer carded and replaced by pennantite plus poly ric) on the arbitrary division of 4% Fe*Os is type stacking symbol. rejected by Foster (1962), because ferric iron Frondel (1955) has described the mineral commonly substitutes for aluminum in many gonyerite (Mm.ssMgi.ssFe^Zn.MPb.ojCu.oOs.oifSia.Ts chamosites. Varietal names that should be dis Fe.i7Al.o8)401o.2o(OH)7.8o as a trioctahedral chlo carded include daphnite which is a chamosite, rite. However the ;t-ray diffraction powder data orthochamosite which is the polytype chamosite of this mineral shows that it is not a chlorite. lb, pseudothuringite which is an aluminian cha This has been confirmed with single crystals mosite, and thuringite which is a ferric alumi from the type material of Frondel by Bailey nian chamosite. (personal communication). Varietal names have been given to composi tions in the magnesium-ferrous iron solid-solu Conclusions tion series between clinochlore and chamosite. Varietal names that should be discarded include There are descriptions at present for four dis brunsvigite which is a magnesian chamosite, co- tinct chemical species within the trioctahedral rundophilite (often misspelled as corundophyl- chlorite group. With the use of chemical ele lite) which is an iron aluminian clinochlore, de ment adjectives, the complete range of chemical lessite which is an iron clinochlore, diabantite varieties may be described, so that all special which is a magnesian siliconian chamosite, pyc- varietal names should be discarded. In addition, nochlorite which is an iron clinochlore, and ri- the polytype symbol should be stated if it can be pidolite which is either an iron-aluminian clino determined. Until the symbol nomenclature is chlore or a magnesium-aluminian chamosite. agreed upon by the joint committee of the Inter Minor substitution of aluminum by chromium national Mineralogical Association and the In in clinochlore occurs in the varieties kammere- ternational Union of Crystallography, the sym rite and kotchubeite. These names should be dis bols of Brown & Bailey (1962) may be used. The carded in favour of chromian clinochlore. A use of prefixes such as ortho in front of cha proposal to redefine these varieties on an arbi mosite instead of suffixed symbols to indicate trary division of 2% Crj03 minimum was made the polytype must be avoided. The general for by Lapham (1958), who suggested that the mula for the trioctahedral chlorite group is chromium occupies octahedral positions in kam- [(Mg,Fe+ +,Mn,Ni)..x-yfAl,Fe+ ++,CrJr] [(Si^fAl) mererite but tetrahedral positions in kotchu z]Oio(OH)8. Foster (1962) gives the range of Z beite. This subdivision is extremely unlikely, as 1.6 > Z > 0.6, and states that the number because the crystal field stability energy of of octahedral cations which is normally 6.0 may Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/2/178/3445639/178.pdf by guest on 28 September 2021 180 THE CANADIAN MINERALOGIST drop to as low as 5.6 with X number of vacant Frondel, C. (1955): Two chlorites: gonyerite and octahedral sites. melanolite. Amer. Mineral. 40, 1090-1094. Hey, M. H. (1954): A new review of the chlorites.
Recommended publications
  • Fire Retardancy of Polypropylene/Kaolinite Composites Marcos Batistella, Belkacem Otazaghine, Rodolphe Sonnier, Carlos Petter, José-Marie Lopez-Cuesta
    Fire retardancy of polypropylene/kaolinite composites Marcos Batistella, Belkacem Otazaghine, Rodolphe Sonnier, Carlos Petter, José-Marie Lopez-Cuesta To cite this version: Marcos Batistella, Belkacem Otazaghine, Rodolphe Sonnier, Carlos Petter, José-Marie Lopez-Cuesta. Fire retardancy of polypropylene/kaolinite composites. Polymer Degradation and Stability, Elsevier, 2016, 129, pp.260-267. 10.1016/j.polymdegradstab.2016.05.003. hal-02906432 HAL Id: hal-02906432 https://hal.archives-ouvertes.fr/hal-02906432 Submitted on 26 May 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Fire retardancy of polypropylene/kaolinite composites * Marcos Batistella a, c, , Belkacem Otazaghine b, Rodolphe Sonnier b, Carlos Petter c, Jose-Marie Lopez-Cuesta b a Federal University of Santa Catarina, R. Eng. Agronomico^ Andrei Cristian Ferreira, s/n e Trindade, Florianopolis, SC, CEP 88040-900, Brazil b Ecole des Mines d’Ales, Centre des Materiaux (C2MA) e Pole^ Materiaux Polymeres Avances, 6 Avenue de Clavieres, 30319, Ales Cedex, France c Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, CEP 91501-970, Brazil abstract In this study the influence of surface modification of kaolinite with trisilanolisooctyl Polyhedral Oligo- SilSesquioxane (POSS) in polypropylene composites was evaluated in terms of thermal stability and fire retardancy and compared with talc.
    [Show full text]
  • Evaluation of Selected Kaolin Clays As a Raw Material for the Turkish Cement and Concrete Industry
    Evaluation of Selected Kaolin Clays as a Raw Material for the Turkish Cement and Concrete Industry Aydin Aras1, Mustafa Albayrak1, Metin Arikan2, Konstantin Sobolev3 * 1 General Directorate of Mineral Research and Exploration (MTA), Turkey 2 Civil Engineering Department, Middle East Technical University (METU), Turkey 3 Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon (UANL), Mexico ABSTRACT Turkey has a long tradition (starting from the prehistoric civilizations) and experience in exploring and processing clay raw materials into ceramic products. Many of these products, such as tiles and sanitary ware, are manufactured for domestic and export markets. Kaolin clay is one of the raw materials of major importance for the ceramic and paper industry, as well as for a number of auxiliary applications. There is an ongoing interest to apply kaolin clay in the construction industry as a raw material for the production of white cement clinker and as an artificial pozzolanic additive for concrete (in a form of metakaolin). This report presents the results related to search, assessment and evaluation of available resources for advanced cement and concrete additives. Keywords: kaolin, metakaolin, construction, resources, ceramics, cement, x-ray diffraction, SEM INTRODUCTION Turkey has an abundance of natural resources and its mining industry is one of the sectors showing steady growth. Among the most commonly mined minerals are borax, magnesite, chromites, barite, feldspars, different clays, and limestone [1-21]. Local ceramic industry has more than 4000 years of experience in exploring and processing widely available raw materials into useful commodities. Currently, several ceramic products, such as tiles and sanitary ware are manufactured to meet international standards (ISO 9000) and significant amounts (about 45 %) of these products are exported [21].
    [Show full text]
  • Clay Minerals Soils to Engineering Technology to Cat Litter
    Clay Minerals Soils to Engineering Technology to Cat Litter USC Mineralogy Geol 215a (Anderson) Clay Minerals Clay minerals likely are the most utilized minerals … not just as the soils that grow plants for foods and garment, but a great range of applications, including oil absorbants, iron casting, animal feeds, pottery, china, pharmaceuticals, drilling fluids, waste water treatment, food preparation, paint, and … yes, cat litter! Bentonite workings, WY Clay Minerals There are three main groups of clay minerals: Kaolinite - also includes dickite and nacrite; formed by the decomposition of orthoclase feldspar (e.g. in granite); kaolin is the principal constituent in china clay. Illite - also includes glauconite (a green clay sand) and are the commonest clay minerals; formed by the decomposition of some micas and feldspars; predominant in marine clays and shales. Smectites or montmorillonites - also includes bentonite and vermiculite; formed by the alteration of mafic igneous rocks rich in Ca and Mg; weak linkage by cations (e.g. Na+, Ca++) results in high swelling/shrinking potential Clay Minerals are Phyllosilicates All have layers of Si tetrahedra SEM view of clay and layers of Al, Fe, Mg octahedra, similar to gibbsite or brucite Clay Minerals The kaolinite clays are 1:1 phyllosilicates The montmorillonite and illite clays are 2:1 phyllosilicates 1:1 and 2:1 Clay Minerals Marine Clays Clays mostly form on land but are often transported to the oceans, covering vast regions. Kaolinite Al2Si2O5(OH)2 Kaolinite clays have long been used in the ceramic industry, especially in fine porcelains, because they can be easily molded, have a fine texture, and are white when fired.
    [Show full text]
  • Kaolinite Al2si2o5(OH)4 C 2001 Mineral Data Publishing, Version 1.2 ° Crystal Data: Triclinic
    Kaolinite Al2Si2O5(OH)4 c 2001 Mineral Data Publishing, version 1.2 ° Crystal Data: Triclinic. Point Group: 1: Rarely as crystals, thin platy or stacked, to 2 mm. More commonly as microscopic pseudohexagonal plates and clusters of plates, aggregated into compact, claylike masses. Physical Properties: Cleavage: Perfect on 001 . Tenacity: Flexible but inelastic. Hardness = 2{2.5 D(meas.) = 2.61{2.68 D(caflc.) =g 2.63 Optical Properties: Transparent to translucent as single crystals. Color: White to tan, may be variously colored by impurities. Luster: Pearly to dull earthy. Optical Class: Biaxial ({). Orientation: X c = 13± to 10±; Y a = 1±{4±. Dispersion: r > v; weak. ® = 1.553{1.565^ ¯ =¡1.559{1¡.569 ° =^ 1.560{1.570 2V(meas.) = 24±{50± Cell Data: Space Group: P 1: a = 5.15 b = 8.95 c = 7.39 ® = 91:8± ¯ = 104:5± 105:0± ° = 90± Z = [2] ¡ X-ray Powder Pattern: Scalby, Yorkshire, England (1A). 7.16 (vvs), 3.573 (vvs), 4.336 (vs), 2.491 (s), 2.289 (s), 2.558 (ms), 2.379 (ms) Chemistry: (1) SiO2 45.80 Al2O3 39.55 Fe2O3 0.57 FeO 0.18 MgO 0.14 CaO 0.41 K2O 0.03 + H2O 13.92 H2O¡ 0.17 Total 100.77 3+ (1) Mikawo mine, Niigata Prefecture, Japan; corresponds to (Al2:00Fe0:02Mg0:01Ca0:02)§=2:05 Si2O5(OH)3:99: Polymorphism & Series: Dickite, halloysite, and nacrite are polymorphs. Mineral Group: Kaolinite-serpentine group. Occurrence: Replaces other aluminosilicate minerals during hydrothermal alteration and weathering. A common constituent of the clay-size fraction of sediments, where it may be formed by direct precipitation.
    [Show full text]
  • The Influence of Halloysite Content on the Shear Strength of Kaolinite
    Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 1981 The influence of halloysite content on the shear strength of kaolinite Reka Katalin Gabor Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Geology Commons, and the Materials Science and Engineering Commons Let us know how access to this document benefits ou.y Recommended Citation Gabor, Reka Katalin, "The influence of halloysite content on the shear strength of kaolinite" (1981). Dissertations and Theses. Paper 3215. https://doi.org/10.15760/etd.3206 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. AN ABSTRACT OF THE THESIS OF Reka Katalin Gabor for the Master of Science in Geology presented October 6, 1981. Title: The Influence of Halloysite Content on the Shear Strength of Kaolinite. APPROVED BY MEMBERS OF THE THESIS COMMITTEE: The objective of this thesis is to determine the rel­ ative shear strengths of halloysite, kaolinite, synthetic mixtures, and local soils, to investigate the influence of halloysite content on the shear strength of kaolinite, and to explore the possibility that the strength properties of soil clays might be controlled by the relative content of their component minerals. Sets of samples of pure kaolinite and halloysite min­ erals and their mixtures in proportions of 1:1, 3:1, and 2 1:3 were prepared in the Harvard Miniature Compaction de­ vice, each compacted in four separate layers with 35 tamp- ings from the 30 pound spring compactor on each layer.
    [Show full text]
  • Effect of Kaolinite and Ca-Montmorillonite on the Alleviation of Soil Water Repellency
    Effect of kaolinite and Ca-montmorillonite on the alleviation of soil water repellency P. Dlapa1, S.H. Doerr2, Ľ. Lichner3, M. Šír4, M. Tesař4 1Faculty of Natural Science, Comenius University, Bratislava, Slovakia 2Department of Geography, University of Wales Swansea, Swansea, UK 3Institute of Hydrology, Slovak Academy of Sciences, Bratislava, Slovakia 4Institute for Hydrodynamics, Academy of Sciences of the Czech Republic, Prague, Czech Republic ABSTRACT The effects of adding 1–3% (weight) kaolinite or Ca-montmorillonite on the we�ability of silica sand, made highly water repellent with stearic acid, was studied during we�ing and prolonged drying phases at 50°C. The persistence of water repellency was estimated with the water drop penetration time (WDPT) test. A�er we�ing water repellency disappeared in all the samples. During the drying phase, water repellency re-appeared in all samples (untreated and clay-treated) as the water content decreased below 1%. Repellency did, however, not reach pre-we�ing levels. The effect of clay additions on water repellency differed strongly between the two clay types. Kaolinite reduced WDPT, while Ca-montmorillonite caused an increase in WDPT in the already highly repellent sand. Potential mechanisms for the alleviation effectiveness of kaolinite are proposed, with key factors being the high adhesion forces between water and clay mineral surfaces, and the ability kaolinite to disperse. In the case of Ca-montmorillonite, its lower affinity for water may lead to a displacement of water molecules at mineral surfaces by amphiphilic organic compounds, which may result in increased repellency. This phenomenon clearly requires further investigation. Keywords: water repellency; kaolinite; Ca-montmorillonite; stearic acid The occurrence of water repellency in many soils to wind erosion.
    [Show full text]
  • Rocks Soil Formation Soil Deposits Soil Mineralogy Soil Structure
    Geology; Rocks Soil Mineralogy Soil Formation Soil Soil Structure Deposits Engineering Soil Classification Site Exploration Characterization of Soils Phase Soil Permeability Stresses in Soil Relationships Seepage Masses Stress Strain Behavior of Soils Soil Consolidation Soil Shear Strength 1 Engineering Characterization of Soils Soil Properties that Control its Engineering Behavior Particle Size − Sieve Analysis − Hydrometer Analysis coarse-grained fine-grained Particle/Grain Size Soil Plasticity Distribution Particle Shapes (?) 2 Particle Size; Standard Sieve Sizes 3 ASTM Particle Size Classification 4 Sieve Analysis (Mechanical Analysis) This procedure is suitable for coarse grained soils See next slide for ASTM Standard Sieves No.10 sieve …. Has 10 apertures per linear inch 5 ASTM Standard Sieves 6 Hydrometer Analysis Also called Sedimentation Analysis Stoke’s Law D2γ (G − G ) v = w s L 18η 7 Grain Size Distribution Curves 8 Terminology C….. Poorly-graded soil D …. Well-graded soil E …. Gap-graded soil D10, D30, D60 = ?? Coefficient of Uniformity, Cu= D60/D10 Coefficient of Curvature, )2 Cc= (D30 /(D10)(D60) 9 Particle Distribution Calculations Example 10 Particle Shapes 11 Clay Formation Clay particles < 2 µm Compared to Sands and Silts, clay size particles have undergone a lot more “chemical weathering”! 12 Clay vs. Sand/Silt Clay particles are generally more platy in shape (sand more equi-dimensional) Clay particles carry surface charge Amount of surface charge depends on type of clay minerals Surface charges that
    [Show full text]
  • Phase Transformations in Silica-Alumina- Magnesia Mixtures As Examined by Continuous X-Ray Diffraction: I
    THE AMERICAN MINERALOGIST, VOL. 47, NOVEMBER-DECEMBER, 1962 PHASE TRANSFORMATIONS IN SILICA-ALUMINA- MAGNESIA MIXTURES AS EXAMINED BY CONTINUOUS X-RAY DIFFRACTION: I. TALC-KAOLINITE COMPOSITIONS R. B. Gnen,lF. M. Wnnr, aNp R. E. Gnru, Uniaersityof Illinois, (Jrbana, I llinois. Ansmacr The phase transformations of natural and synthetic oxide mixtures of talc-kaolinite compositlons were examined by continuous r-ray difiraction while heated to 1450' C. Dif- fraciion intensity data show the enhanced development of protoenstatite within the sheet structure of talc, thus indicating that the growth of this mineral on firing is largely con- trolled by the structure of the talc. The formation temperatule of cordierite, which was used as a measure of the reactivity of various starting materials, indicates that alumina in the form of mullite, rather than as corundum, is most efiective in lowering the develop- ment temperature of this mineral. Additional cordierite formation, through recrystalliza- tion on cooling indicates the presence of an intermediate licluid phase in the formation of this mineral. INrnotucrlow Generalsta,tement . Continuous high-temperature o-ray diffraction methods make it pos- sible to observehigh-temperature reactions as they occur (Wahl et aI., 1961). Previously, high-temperatrte n-ray diffraction has been used mainly for selected observations at some desired temperature and not for continuousobservations of a sampleas it is heated.The techniqueof continuous scanning was used in the present investigation for the study of high-temperaturereactions in talc, kaolinite, talc:kaolinite mixtures, and mixtures of oxides with compositions corresponding to talc and kaolinite. Infl,uence of starting materials Reactionrates between solids are known to be influencedby the nature of the starting materials.
    [Show full text]
  • Mineralogical Studies of Kaolinite-Halloysite Clays: Part Iii
    THE AMERICAN MINERALOGIST, VOL. 50, MAY_JUNE, 1965 MINERALOGICAL STUDIES OF KAOLINITE-HALLOYSITE CLAYS: PART III. A FIBROUS KAOLIN MINERAL FROM PIEDADE, SAO PAULO, BRAZIL PE,nsroDE SouzA SeNros, Instituto ile PesquisasTecnologicas, University of Sd.oPaulo, Sdo Paulo, Brazil, G. W. Bnrnlr.nv, Departmentof Geochemistryand. Minerology, The Pennsylaani,a Slate (Jniaers'ity,Uniaersity Park, Po., aNn HBTBNI oB Souze SaNros, Centro de Microscopia Electronico, (Jn'iversityof Sd,oPaulo. Sao Paulo. Brazil. Arsrn,rcr An unusual form of kaolin mineral, filling cracks in weathered prophyritic granite in the countl, of Piedade, Sdo Paulo, Brazil, consists of visibly fibrous material which, in the electron microscope, appears as thin tubular fibers of considerable length; platy particles are almost entirely absent. X-ray rotation diagrams of dried fiber bundles and selected area electron diffraction patterns of single fibers show an appreciable degree of structural regu- larity in the kaolin layer structure, with 6 as the fiber axis. The results show generar agree- ment with previous data by Honjo, Kitamura and Mihama. Prior to drying, the material as collected can be described as consisting of f endellite and $ halloysite. The endellite com- ponent has the swelling and shrinking behavior characteristic of this mineral with respect to ethylene glycol, water, and gentle heat treatments. This may be the first observation of a mineral of endellite-halloysite type existing in a directly visible fibrous form. INrnolucrror.l An unusual form of kaolin clay
    [Show full text]
  • Clay Minerals
    CLAY MINERALS CD. Barton United States Department of Agriculture Forest Service, Aiken, South Carolina, U.S.A. A.D. Karathanasis University of Kentucky, Lexington, Kentucky, U.S.A. INTRODUCTION of soil minerals is understandable. Notwithstanding, the prevalence of silicon and oxygen in the phyllosilicate structure is logical. The SiC>4 tetrahedron is the foundation Clay minerals refers to a group of hydrous aluminosili- 2 of all silicate structures. It consists of four O ~~ ions at the cates that predominate the clay-sized (<2 |xm) fraction of apices of a regular tetrahedron coordinated to one Si4+ at soils. These minerals are similar in chemical and structural the center (Fig. 1). An interlocking array of these composition to the primary minerals that originate from tetrahedral connected at three corners in the same plane the Earth's crust; however, transformations in the by shared oxygen anions forms a hexagonal network geometric arrangement of atoms and ions within their called the tetrahedral sheet (2). When external ions bond to structures occur due to weathering. Primary minerals form the tetrahedral sheet they are coordinated to one hydroxyl at elevated temperatures and pressures, and are usually and two oxygen anion groups. An aluminum, magnesium, derived from igneous or metamorphic rocks. Inside the or iron ion typically serves as the coordinating cation and Earth these minerals are relatively stable, but transform- is surrounded by six oxygen atoms or hydroxyl groups ations may occur once exposed to the ambient conditions resulting in an eight-sided building block termed an of the Earth's surface. Although some of the most resistant octohedron (Fig.
    [Show full text]
  • Preparation and Characterization of Kaolinite Nanostructures: Reaction Pathways, Morphology and Structural Order
    Clay Minerals, (2015) 50, 329–340 Preparation and characterization of kaolinite nanostructures: reaction pathways, morphology and structural order BALÁZS ZSIRKA1 , ERZSÉBET HORVÁTH1,*,ÉVAMAKÓ2 , RÓBERT KURDI1 3 AND JÁNOS KRISTÓF 1 Institute of Environmental Engineering, University of Pannonia, H-8201 Veszprém, P.O.Box 158, Hungary 2 Institute of Materials Engineering, University of Pannonia, H-8201 Veszprém, P.O.Box 158, Hungary 3 Department of Analytical Chemistry, University of Pannonia, H-8201 Veszprém, P.O.Box 158, Hungary (Received 8 December 2014; revised 28 April 2015; Associate Editor: H. Stanjek) ABSTRACT: Clay-based nanostructures were prepared from kaolinites of varying structural order by two different methods. In the first method the kaolinite-urea precursor, obtained by dry grinding, was intercalated further with triethanolamine and the tetraalkylammonium salt was synthesized in the interlamellar space. Exfoliation was achieved by the use of sodium polyacrylate (PAS). In the second method, the kaolinite-potassium acetate (kaolinite-KAc) precursor, obtained via two different methods, was intercalated further with ethylene glycol (EG) and then n-hexylamine (HA). Intercalation with EG was also achieved by heating either directly or with microwaves. The morphology that results depends on the method of precursor preparation, the method of heat treatment and the degree of structural order of the original clay. Higher structural order facilitates the formation of a tubular morphology, while mechanical treatment and microwave agitation may result in broken tubes. Molecular mechanical (MM) calculations showed that organo-complexes may be exfoliated to a d value of 10–11 Å. KEYWORDS: intercalation, kaolinite nanostructure, molecular mechanical calculation. The applications of kaolin, a widely used industrial clay 2011) and in catalysts (Nakagaki et al., 2006; Bizaia raw material, depend on its surface reactivity.
    [Show full text]
  • Glossary of Geological Terms
    GLOSSARY OF GEOLOGICAL TERMS These terms relate to prospecting and exploration, to the regional geology of Newfoundland and Labrador, and to some of the geological environments and mineral occurrences preserved in the province. Some common rocks, textures and structural terms are also defined. You may come across some of these terms when reading company assessment files, government reports or papers from journals. Underlined words in definitions are explained elsewhere in the glossary. New material will be added as needed - check back often. - A - A-HORIZON SOIL: the uppermost layer of soil also referred to as topsoil. This is the layer of mineral soil with the most organic matter accumulation and soil life. This layer is not usually selected in soil surveys. ADIT: an opening that is driven horizontally (into the side of a mountain or hill) to access a mineral deposit. AIRBORNE SURVEY: a geophysical survey done from the air by systematically crossing an area or mineral property using aircraft outfitted with a variety of sensitive instruments designed to measure variations in the earth=s magnetic, gravitational, electro-magnetic fields, and/or the radiation (Radiometric Surveys) emitted by rocks at or near the surface. These surveys detect anomalies. AIRBORNE MAGNETIC (or AEROMAG) SURVEYS: regional or local magnetic surveys that measures deviations in the earth=s magnetic field and carried out by flying a magnetometer along flight lines on a pre-determined grid pattern. The lower the aircraft and the closer the flight lines, the more sensitive is the survey and the more detail in the resultant maps. Aeromag maps produced from these surveys are important exploration tools and have played a major role in many major discoveries (e.g., the Olympic Dam deposit in Australia).
    [Show full text]