Hostname: page-component-745bb68f8f-grxwn Total loading time: 0 Render date: 2025-01-08T09:35:55.430Z Has data issue: false hasContentIssue false
  • English
  • Français

The Crystal Structure of Talc

Published online by Cambridge University Press:  01 July 2024

J. H. Rayner  and
G. Brown
J. H. Rayner
Affiliation:
Pedology Department, Rothamsted Experimental Station, Harpenden, Herts, England
G. Brown
Affiliation:
Pedology Department, Rothamsted Experimental Station, Harpenden, Herts, England
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The crystal structure of a sample of talc from Harford County, Maryland, has been determined by least squares refinement from X-ray diffraction photographs. A triclinic cell with a = 5·293, b = 9·179, c = 9·496Å, α = 90·57°, β = 98·91°, γ = 90·03, space group C1̄ is adopted. The layers of the structure have almost monoclinic symmetry but the nearly hexagonal rings of oxygen atoms on the surfaces of the layers, formed by the bases of the silica tetrahedra, are not held in register by interlayer ions as they are in micas but are partly displaced so that the stack of layers forms a triclinic crystal. The hexagons of surface oxygens are distorted by a 3·4° twist of the tetrahedra so that the b axis is 0·2 per cent shorter than in a structure with regular hexagons, and the twist brings the oxygen ions a little closer to the octahedral magnesium ions.

Résumé

Résumé

La structure cristalline d’un échantillon de talc du Harford County, Maryland, a été déterminée par un raffinement par moindres carrés à partir de clichés photographiques de diffraction des rayons X. On a adopté une maille triclinique de groups C1̄, avec a = 5,293 Å, b = 9,179 Å, c = 9,496 Å, α = 90,57°, β = 98,91° et γ = 90,03°.

Les couches de la structure ont presque une symétrie monoclinique, mais les anneaux d’atomes d’oxygène de surface, d’une forme voisine de l’hexagone, formés par les bases des tétraèdres de silice ne sont pas en correspondance exacte comme ils le sont dans les micas où se trouvent des ions interfeuillets; ils sont au contraire déplacés en partie, si bien que l’empilement des feuillets forme un cristal triclinique. Les hexagones des atomes d’oxygène de surface sont déformés à cause d’une rotation des tétraèdes de 3,4°; ainsi l’axe b est plus court de 0,2% de ce qu’il est dans une structure à hexagones réguliers, et la rotation des tétraèdres rapproche un petit peu les ions oxygène des ions magnésium octaédriques.

Kurzreferat

Kurzreferat

Die Kristallstruktur einer Talkprobe aus Harford County, Maryland, wurde aus Röntgenbeugungsaufnahmen unter Berechnung der kleinsten Abweichungsquadrate bestimmt. Es wurde eine trikline Zelle mit a = 5,293, b = 9,179, c = 9,496 Å, α = 90,57°, β = 98,91° und γ = 90,03°, Raumgruppe C1 angenommen. Die Schichten dieser Struktur haben fast monokline Symmetrie, doch werden die nahezu hexagonalen Ringe der Sauerstoffatome an den durch die Grundflächen der Si-Tetraeder gebildeten Schichtoberflächen nicht durch Zwischenschichtionen aufeinander ausgerichtet, wie dies bei den Glimmern der Fall ist. Sie sind vielmehr teilweise versetzt, so daß die Schichtfolge einen triklinen Kristall bildet. Die Sechsecke der Oberflächensauerstoffe sind durch eine 3,4°-Drehung der Tetraeder verzerrt, so daß die b-Achse um 0,2% kürzer ist als in einer Struktur mit regelmäßigen Sechsecken. Die Drehung bringt die Sauerstoffionen etwas näher an die oktaedrischen Magnesiumionen heran.

Резюме

Резюме

Структура кристаллов талька определялась при помощи рентгенографии по образцу из харфордского округа, Мэриланд. Принята триклинная клетка с a = 5,293, b = 9,179, с = 9,496 Å, α = 90,57°, β = 98,91°, γ = 90,03, промежуток группы С 1. Слои структуры имеют почти что моноклинную симметрию, но на поверхности слоев имеются примерно шестигранные кольца атомов кислорода, которые не содержатся в равновесии в межслойных ионах как в слюде, а частично смещены, так что столбик слоя образует триклинный кристалл. Шестигранники поверхностных кислородов искажены скручиванием тетраэдры на 3,4°, таким образом ось b на 0,2 % короче, чем структура с регулярными шестигранниками, а скручивание слегка приближает ионы кислорода к октаэдральным ионам магния.

Type
Research Article
Information
Clays and Clay Minerals , Volume 21 , Issue 2 , April 1973 , pp. 103 - 114
Copyright
Copyright © 1973 The Clay Minerals Society

References

Aleixandre, V. and Alvarez Estrada, D., (1952) Estudos sobre talcos españoles y sus aplicaciones en dieléctricos para La alta frecuencia Madrid Consejo Superior de Investigaciones Cientificas.Google Scholar
Amelinckx, S. and Delavignette, P., (1961) Electron microscope observation of dislocations in talc J. appl. Phys. 32 341–351.CrossRefGoogle Scholar
Bailey, S. W., (1966) The status of clay mineral structures Clays and Clay Minerals 14 1–23.CrossRefGoogle Scholar
Brindley, G. W., Oughton, B. M. and Robinson, K., (1950) Polymorphism of the chlorites—I. Ordered structures Acta Crystallogr. 3 408–416.CrossRefGoogle Scholar
Brindley, G. W. and Wardle, R., (1970) Monclinic and triclinic pyrophyllite Am. Mineralogist 55 1259–1272.Google Scholar
Brown, B. E. and Bailey, S. W., (1963) Chlorite polytypism—II. Crystal structure of a one layer Crchlorite Am. Mineralogist 48 42–61.Google Scholar
Brown, G., (1965) Significance of recent structure determinations of layer silicates for clay studies Clay Minerals 6 73–82.CrossRefGoogle Scholar
Burnham, C. W. and Radoslovich, E. W., (1964) Crystal structures of coexisting muscovite and paragonite Carnegie Institute Year Book 63 232–236.Google Scholar
Coxeter, H. S. M., (1948) Regular Polytopes London Methuen.Google Scholar
Deer, W. A., Howie, R. A. and Zussman, J., (1962) Rock Forming Minerals—III. Sheet Silicates London Longmans.Google Scholar
Donnay, J. D. H. Donnay, G., Cox, E. G., Kennard, O. and King, M. V., (1963) Crystal Data Determinative Tables 2nd Edn.Google Scholar
Donnay, G., Donnay, J. D. H. and Takeda, H., (1964) Trioctahedral one layer micas—II. Prediction of the structure from composition and cell dimensions Acta Crystallogr. 17 1374–1381.CrossRefGoogle Scholar
Donnay, G., Morimoto, N., Takeda, H. and Donnay, J. D. H., (1964) Trioctahedral one layer micas—I. Crystal structure of a synthetic ion mica Acta Crystallogr 17 1369–1373.CrossRefGoogle Scholar
Drits, V. A., (1969) Some general remarks on the structure of trioctahedral micas Proc. (Tokyo) International Clay Conference Jerusalem Israel U.P. 51–59.Google Scholar
El-Attar, H. A., Jackson, M. L. and Volk, V. V., (1972) Fluorine loss from silicates on ignition Am. Mineralogist 57 246–252.Google Scholar
Farmer, V. C., (1958) The infra-red spectra of talc, saponite and hectorite Mineralog. Mag. 31 829–945.Google Scholar
Farmer, V. C. and Russell, J. D., (1964) The infra-red spectra of layer silicates Spectrochimica Acta 20 1149–1173.10.1016/0371-1951(64)80165-XCrossRefGoogle Scholar
Gruner, J. W., (1934) The crystal structures of talc and pyrophyllite Zeit. Krist. 88 412–419.Google Scholar
Hamilton, W. C. and Abraham, S. G., (1970) International Union of Crystallography Single Crystal Intensity Project—II. Least squares refinements of structural parameters Acta. Crystallogr A26 18–24.CrossRefGoogle Scholar
Hendricks, S. B., (1938) On the crystal structure of talc and pyrophyllite Zeit Krist. 99 264–274.Google Scholar
Hendricks, S. B., (1940) Variable structures and continuous scattering from layer silicate lattices Phys. Rev. 57 448–454.CrossRefGoogle Scholar
Henry, N. F. and Lonsdale, K., (1952) International tables for X-ray crystallography—1. Symmetry Groups .Google Scholar
Kennard, O., Speakman, J. C. and Donnay, J. D. H., (1967) Primary crystallographic data Acta. Crystallogr. 22 445–449.CrossRefGoogle Scholar
Kodama, H. and Oinuma, K., (1963) Identification of kaolin minerals in clays by X-ray and infra-red spectroscopy Clays and Clay Minerals 11 236–249.Google Scholar
McCauley, J. W. and Newnham, R. E., (1971) Origin and prediction of ditrigonal distortion in micas Am. Mineralogists 1626–1638.Google Scholar
Mackenzie, R. C., (1957) Editor The Differential Thermal Investigation of Clays London Mineralogical Society, Clay Minerals Group.Google Scholar
Pauling, L., (1930) The structure of micas and related minerals Proc. Nat.Aca. Sci. U.S. 16 123–129.CrossRefGoogle ScholarPubMed
Radoslovich, E. W., (1962) The cell dimensions and symmetry of layer lattice silicates—II. Regression relations Am. Mineralogist 47 617–636.Google Scholar
Rayner, J. H. and Brown, G., (1964) Structure of pyrophyllite Clays and Clay Minerals 13 73–84.Google Scholar
Rayner, J. H. and Brown, G., (1966) Triclinic form of talc Nature, Lond. 212 1352–1353.CrossRefGoogle Scholar
Rayner, J. H. The crystal structure of phlogopite (to be published).Google Scholar
Ross, M., Smith, W. L. and Ashton, W. H., (1968) Triclinic talc and associated amphiboles from Gouverneur mining district, New York Am. Mineralogist 53 751–769.Google Scholar
Sclar, C. B., Carrison, L. C. and Schwartz, C. M., (1965) Phase equilibria in the system MgO-SiO2-H2O, 20–130Kb, 350–1300°C. Basic Sci. Div. American Ceramic Society (Sept. 65) .Google Scholar
Shirozu, H. and Bailey, S. W., (1966) Crystal structure of a two layer Mg-vermiculite Am. Mineralogist 51 1124–1143.Google Scholar
Smith, J. V. and Bailey, S. W., (1963) Second review of Al-O and Si-O tetrahedral distances Acta. Crystallogr. 16 801–811.CrossRefGoogle Scholar
Steinfink, H., (1962) The crystal structure of a trioctahedral mica: phlogopite Am. Mineralogist 47 886–896.Google Scholar
Stewart, R. F., Davidson, E. R. and Simpson, W. T., (1965) Coherent scattering for the hydrogen atom in the hydrogen molecule J. Chem. Phys. 42 3175–3187.CrossRefGoogle Scholar
Takeuchi, Y. and Sadanaga, R., (1966) Structural studies of brittle micas (1) the structure of Xanthophyllite refined Min. Journ. 4 424–437.Google Scholar
Wardle, R. and Brindley, G. W., (1972) The crystal structures of pyrophyllite, ITc and of its dehydroxylate Am. Mineralogist 57 732–750.Google Scholar
Wilkins, R. W. T., (1967) The hydroxyl-stretching region of the biotite mica spectrum Mineralog. Mag 36 325–333.Google Scholar
Wilkins, R. W. T. and Ito, J., (1967) Infra-red spectra of some synthetic talcs Am. Mineralogist 52 1649–1661.Google Scholar
Zigan, F. and Rothbauer, R., (1967) Neutronenbeugungsmessungen an Brucit N. Jb. Miner. Mh. 4/5 137–143.Google Scholar