TEM and X-ray study of syntactic intergrowths of epistolite, murmanite and shkatulkalite

Pèter Nèmeth, Giovanni Ferraris, G. Radnóczi, Olga A. Ageeva

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Selected-area electron diffraction (SAED) patterns obtained on samples of the heterophyllosilicates epistolite and murmanite from Mt. Malyi Punkaruaiv, Lovozero massif, in the Kola Peninsula of Russia, invariably show broad, streaked and split diffraction-spots and reveal oriented intergrowths (syntaxy) between the two minerals and of epistolite with minor shkatulkalite (likely a heterophyllosilicate as well). These results are confirmed by X-ray single-crystal and powder-diffraction data. We show that the syntaxy is favored by the presence in epistolite, munnanite and shkatulkalite of common supercells, which leads to a systematic overlap of diffraction spots belonging to different intergrown minerals. The structure determination of epistolite and murmanite by using "single-crystal" diffraction intensities contributed also by minor intergrown phases shows substantial residual peaks of electron density and some short bond-lengths. The difficulties encountered in properly refining the structures of the main phases re related to the unresolved contributions of the minor intergrown phases to the diffracted intensities. We suggest the ideal formulae (Na,□)2(Na,Ti)4[Nb2(O,H2 O)4Si4O14](OH,F)2• 2H2O for epistolite and (Na,□)2 (Na,Ti)4[Ti2(O,H2O)4 Si4O14](OH,F)2•2 H2O for murmanite.

Original languageEnglish
Pages (from-to)973-987
Number of pages15
JournalCanadian Mineralogist
Volume43
Issue number3
Publication statusPublished - Jun 2005

Fingerprint

Syntactics
diffraction
transmission electron microscopy
Diffraction
Transmission electron microscopy
X rays
Minerals
Single crystals
Bond length
Electron diffraction
Diffraction patterns
Refining
Carrier concentration
crystal
supercell
mineral
electron density
electron

Keywords

  • Crystal structure
  • Electron microscopy
  • Epistolite
  • Epitaxy
  • Heterophyllosilicates
  • Mero-plesiotype series
  • Murmanite
  • Shkatulkalite
  • Titanosilicates

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

TEM and X-ray study of syntactic intergrowths of epistolite, murmanite and shkatulkalite. / Nèmeth, Pèter; Ferraris, Giovanni; Radnóczi, G.; Ageeva, Olga A.

In: Canadian Mineralogist, Vol. 43, No. 3, 06.2005, p. 973-987.

Research output: Contribution to journalArticle

Nèmeth, Pèter ; Ferraris, Giovanni ; Radnóczi, G. ; Ageeva, Olga A. / TEM and X-ray study of syntactic intergrowths of epistolite, murmanite and shkatulkalite. In: Canadian Mineralogist. 2005 ; Vol. 43, No. 3. pp. 973-987.
@article{119694e150e04779bfe8f78b04c83cdd,
title = "TEM and X-ray study of syntactic intergrowths of epistolite, murmanite and shkatulkalite",
abstract = "Selected-area electron diffraction (SAED) patterns obtained on samples of the heterophyllosilicates epistolite and murmanite from Mt. Malyi Punkaruaiv, Lovozero massif, in the Kola Peninsula of Russia, invariably show broad, streaked and split diffraction-spots and reveal oriented intergrowths (syntaxy) between the two minerals and of epistolite with minor shkatulkalite (likely a heterophyllosilicate as well). These results are confirmed by X-ray single-crystal and powder-diffraction data. We show that the syntaxy is favored by the presence in epistolite, munnanite and shkatulkalite of common supercells, which leads to a systematic overlap of diffraction spots belonging to different intergrown minerals. The structure determination of epistolite and murmanite by using {"}single-crystal{"} diffraction intensities contributed also by minor intergrown phases shows substantial residual peaks of electron density and some short bond-lengths. The difficulties encountered in properly refining the structures of the main phases re related to the unresolved contributions of the minor intergrown phases to the diffracted intensities. We suggest the ideal formulae (Na,□)2(Na,Ti)4[Nb2(O,H2 O)4Si4O14](OH,F)2• 2H2O for epistolite and (Na,□)2 (Na,Ti)4[Ti2(O,H2O)4 Si4O14](OH,F)2•2 H2O for murmanite.",
keywords = "Crystal structure, Electron microscopy, Epistolite, Epitaxy, Heterophyllosilicates, Mero-plesiotype series, Murmanite, Shkatulkalite, Titanosilicates",
author = "P{\`e}ter N{\`e}meth and Giovanni Ferraris and G. Radn{\'o}czi and Ageeva, {Olga A.}",
year = "2005",
month = "6",
language = "English",
volume = "43",
pages = "973--987",
journal = "Canadian Mineralogist",
issn = "0008-4476",
publisher = "Mineralogical Association of Canada",
number = "3",

}

TY - JOUR

T1 - TEM and X-ray study of syntactic intergrowths of epistolite, murmanite and shkatulkalite

AU - Nèmeth, Pèter

AU - Ferraris, Giovanni

AU - Radnóczi, G.

AU - Ageeva, Olga A.

PY - 2005/6

Y1 - 2005/6

N2 - Selected-area electron diffraction (SAED) patterns obtained on samples of the heterophyllosilicates epistolite and murmanite from Mt. Malyi Punkaruaiv, Lovozero massif, in the Kola Peninsula of Russia, invariably show broad, streaked and split diffraction-spots and reveal oriented intergrowths (syntaxy) between the two minerals and of epistolite with minor shkatulkalite (likely a heterophyllosilicate as well). These results are confirmed by X-ray single-crystal and powder-diffraction data. We show that the syntaxy is favored by the presence in epistolite, munnanite and shkatulkalite of common supercells, which leads to a systematic overlap of diffraction spots belonging to different intergrown minerals. The structure determination of epistolite and murmanite by using "single-crystal" diffraction intensities contributed also by minor intergrown phases shows substantial residual peaks of electron density and some short bond-lengths. The difficulties encountered in properly refining the structures of the main phases re related to the unresolved contributions of the minor intergrown phases to the diffracted intensities. We suggest the ideal formulae (Na,□)2(Na,Ti)4[Nb2(O,H2 O)4Si4O14](OH,F)2• 2H2O for epistolite and (Na,□)2 (Na,Ti)4[Ti2(O,H2O)4 Si4O14](OH,F)2•2 H2O for murmanite.

AB - Selected-area electron diffraction (SAED) patterns obtained on samples of the heterophyllosilicates epistolite and murmanite from Mt. Malyi Punkaruaiv, Lovozero massif, in the Kola Peninsula of Russia, invariably show broad, streaked and split diffraction-spots and reveal oriented intergrowths (syntaxy) between the two minerals and of epistolite with minor shkatulkalite (likely a heterophyllosilicate as well). These results are confirmed by X-ray single-crystal and powder-diffraction data. We show that the syntaxy is favored by the presence in epistolite, munnanite and shkatulkalite of common supercells, which leads to a systematic overlap of diffraction spots belonging to different intergrown minerals. The structure determination of epistolite and murmanite by using "single-crystal" diffraction intensities contributed also by minor intergrown phases shows substantial residual peaks of electron density and some short bond-lengths. The difficulties encountered in properly refining the structures of the main phases re related to the unresolved contributions of the minor intergrown phases to the diffracted intensities. We suggest the ideal formulae (Na,□)2(Na,Ti)4[Nb2(O,H2 O)4Si4O14](OH,F)2• 2H2O for epistolite and (Na,□)2 (Na,Ti)4[Ti2(O,H2O)4 Si4O14](OH,F)2•2 H2O for murmanite.

KW - Crystal structure

KW - Electron microscopy

KW - Epistolite

KW - Epitaxy

KW - Heterophyllosilicates

KW - Mero-plesiotype series

KW - Murmanite

KW - Shkatulkalite

KW - Titanosilicates

UR - http://www.scopus.com/inward/record.url?scp=24944555419&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24944555419&partnerID=8YFLogxK

M3 - Article

VL - 43

SP - 973

EP - 987

JO - Canadian Mineralogist

JF - Canadian Mineralogist

SN - 0008-4476

IS - 3

ER -