MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA
Whiskers and needles of F-rich vesuvianite were found together with diopside in cavities of an altered magnesian skarn in the Tas–Khayakhtakh Mountains of Polar Yakutia, in Russia. The acicular crystals are strongly zoned and formed between two generations of diopside. The chemical composition of th...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.569.5929 2023-05-15T18:44:57+02:00 MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA Evgeny V. Galuskin Thomas Armbruster Anna Malsy Irina O. Galuskina The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.569.5929 http://rruff.info/doclib/cm/vol41/CM41_843.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.569.5929 http://rruff.info/doclib/cm/vol41/CM41_843.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://rruff.info/doclib/cm/vol41/CM41_843.pdf text ftciteseerx 2016-01-08T12:25:27Z Whiskers and needles of F-rich vesuvianite were found together with diopside in cavities of an altered magnesian skarn in the Tas–Khayakhtakh Mountains of Polar Yakutia, in Russia. The acicular crystals are strongly zoned and formed between two generations of diopside. The chemical composition of the vesuvianite whiskers is more homogeneous and resembles that of the outermost rim of the vesuvianite needles. In the last stage, fluorapophyllite, prehnite, titanite, calcite and quartz overgrew vesuvianite. Whiskers of vesuvianite crystallized at low activity of CO2 and P–T conditions corresponding to the prehnite– pumpellyite facies. Single-crystal X-ray refinements of the structure of three vesuvianite whiskers, for which electron-micro-probe data also were collected, revealed P4/nnc space-group symmetry and (F, Cl) substitution at O(10) within disordered strings running parallel to the four-fold axis. In addition, there is partial substitution of F at O(11), usually occupied by OH in low-temperature vesuvianite. The high symmetry (P4/nnc) in low-temperature (<350°C) whiskers of vesuvianite adds evidence that the degree of string order is determined not only by the temperature of crystallization, as hitherto assumed, but also by the prevailing composition of the fluid and the regime of crystal growth leading to substitutions that disturb intra-rod order and particularly long-range rod order. Long-range rod order leads to reduced symmetry (P4/n or P4nc), typical of vesuvianite crystal-lized at low temperature in rodingites. Vesuvianite whiskers formed in a kinetic regime where the growth rates were selectively Text Yakutia Unknown |
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Open Polar |
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ftciteseerx |
language |
English |
description |
Whiskers and needles of F-rich vesuvianite were found together with diopside in cavities of an altered magnesian skarn in the Tas–Khayakhtakh Mountains of Polar Yakutia, in Russia. The acicular crystals are strongly zoned and formed between two generations of diopside. The chemical composition of the vesuvianite whiskers is more homogeneous and resembles that of the outermost rim of the vesuvianite needles. In the last stage, fluorapophyllite, prehnite, titanite, calcite and quartz overgrew vesuvianite. Whiskers of vesuvianite crystallized at low activity of CO2 and P–T conditions corresponding to the prehnite– pumpellyite facies. Single-crystal X-ray refinements of the structure of three vesuvianite whiskers, for which electron-micro-probe data also were collected, revealed P4/nnc space-group symmetry and (F, Cl) substitution at O(10) within disordered strings running parallel to the four-fold axis. In addition, there is partial substitution of F at O(11), usually occupied by OH in low-temperature vesuvianite. The high symmetry (P4/nnc) in low-temperature (<350°C) whiskers of vesuvianite adds evidence that the degree of string order is determined not only by the temperature of crystallization, as hitherto assumed, but also by the prevailing composition of the fluid and the regime of crystal growth leading to substitutions that disturb intra-rod order and particularly long-range rod order. Long-range rod order leads to reduced symmetry (P4/n or P4nc), typical of vesuvianite crystal-lized at low temperature in rodingites. Vesuvianite whiskers formed in a kinetic regime where the growth rates were selectively |
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The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Evgeny V. Galuskin Thomas Armbruster Anna Malsy Irina O. Galuskina |
spellingShingle |
Evgeny V. Galuskin Thomas Armbruster Anna Malsy Irina O. Galuskina MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA |
author_facet |
Evgeny V. Galuskin Thomas Armbruster Anna Malsy Irina O. Galuskina |
author_sort |
Evgeny V. Galuskin |
title |
MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA |
title_short |
MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA |
title_full |
MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA |
title_fullStr |
MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA |
title_full_unstemmed |
MORPHOLOGY, COMPOSITION AND STRUCTURE OF LOW-TEMPERATURE P4/nnc HIGH-FLUORINE VESUVIANITE WHISKERS FROM POLAR YAKUTIA, RUSSIA |
title_sort |
morphology, composition and structure of low-temperature p4/nnc high-fluorine vesuvianite whiskers from polar yakutia, russia |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.569.5929 http://rruff.info/doclib/cm/vol41/CM41_843.pdf |
genre |
Yakutia |
genre_facet |
Yakutia |
op_source |
http://rruff.info/doclib/cm/vol41/CM41_843.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.569.5929 http://rruff.info/doclib/cm/vol41/CM41_843.pdf |
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