<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>Atoll garnets in aposkarn serpentinite from the Wiluy River, Republic of Sakha-Yakutia, Russia, have the classic form comprising a garnet core, an intermediate zone filled with chlorite-group minerals and an outer garnet atoll. The core of an illustrated example is complexly zoned from schorlomite to grossular-andradite. Morphologically, the core is a rhombic dodecahedral crystal. The atoll crystallized as a tetragon-trisoctahedron with minor rhombic dodecahedron faces and is composed of hibschite and "hydroandradite". The atoll garnet formed as the result of selective dissolution and substitution by chlorite of an internal hibschite zone with columnar structure that became unstable under new conditions of crystallization. The pattern of dissolution traces defects in the garnet crystal. The growth of the atoll garnets reflects the main stages in the evolution of the Wiluy deposit itself and is associated with the development of the Siberian traps.</p></abstract>

Atoll garnets in aposkarn serpentinite from the Wiluy River, Republic of Sakha-Yakutia, Russia, have the classic form comprising a garnet core, an intermediate zone filled with chlorite-group minerals and an outer garnet atoll. The core of an illustrated example is complexly zoned from schorlomite to grossular-andradite. Morphologically, the core is a rhombic dodecahedral crystal. The atoll crystallized as a tetragon-trisoctahedron with minor rhombic dodecahedron faces and is composed of hibschite and "hydroandradite". The atoll garnet formed as the result of selective dissolution and substitution by chlorite of an internal hibschite zone with columnar structure that became unstable under new conditions of crystallization. The pattern of dissolution traces defects in the garnet crystal. The growth of the atoll garnets reflects the main stages in the evolution of the Wiluy deposit itself and is associated with the development of the Siberian traps.

Atoll Garnets in "Achtarandite" Serpentinites: Morphology, Composition and Mode of Origin

Faculty of Earth Sciences, University of Silesia, ul. Będzińska 60, 41-200 Sosnowiec, Poland

Mineralogy and Petrology, Institute of Geochemistry, Al. Żwirki i Wigury 93, 02-089 Warszawa, Poland

Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland

Mineralogia

Atoll garnets in aposkarn serpentinite from the Wiluy River, Republic of Sakha-Yakutia, Russia, have the classic form comprising a garnet core, an intermediate...

Atoll Garnets in "Achtarandite" Serpentinites: Morphology, Composition and Mode of Origin

Pubblicato online: 21 nov 2008

Pagine: 139 - 150

DOI: https://doi.org/10.2478/v10002-007-0022-9

Parole chiave
atoll garnet, morphology, hibschite, Raman spectroscopy, serpentinite, Wiluy River, Russia

This content is open access.

Atoll Garnets in "Achtarandite" Serpentinites: Morphology, Composition and Mode of Origin

Pubblicato online: 21 nov 2008

Pagine: 139 - 150

DOI: https://doi.org/10.2478/v10002-007-0022-9

Parole chiaveatoll garnet, morphology, hibschite, Raman spectroscopy, serpentinite, Wiluy River, Russia

This content is open access.

Parole chiave
atoll garnet, morphology, hibschite, Raman spectroscopy, serpentinite, Wiluy River, Russia