Please use this identifier to cite or link to this item:
http://hdl.handle.net/2445/160531
Title: | Ni-phyllosilicates (garnierites) from the Falcondo Ni-laterite deposit (Dominican Republic): Mineralogy, nanotextures, and formation mechanisms by HRTEM and AEM |
Author: | Villanova de Benavent, Cristina Nieto, Fernando Viti, Cecilia Proenza Fernández, Joaquín Antonio Galí Medina, Salvador, 1949- Roqué, Josep |
Keywords: | Níquel Mineralogia República Dominicana Nickel Mineralogy Dominican Republic |
Issue Date: | 1-May-2016 |
Publisher: | Mineralogical Society of America |
Abstract: | Ni-bearing magnesium phyllosilicates (garnierites) are significant Ni ores in Ni-laterites worldwide. The present paper reports a detailed TEM investigation of garnierites from the Falcondo Ni-laterite deposit (Dominican Republic). Different types of garnierites have been recognized, usually consisting of mixtures between serpentine and talc-like phases that display a wide range of textures at the nano meter scale. In particular, chrysotile tubes, polygonal serpentine, and lizardite lamellae are intergrown with less crystalline, talc-like lamellae. Samples consisting uniquely of talc-like and of sepiolite-falcondoite were also observed, occurring as distinctive thin lamellae and long ribbon-shaped fibers, respectively. HRTEM imaging indicates that serpentine is replaced by the talc-like phase, whereas TEM-AEM data show preferential concentration of Ni in the talc-like phase. We suggest, therefore, that the crystallization of Ni-bearing phyllosilicates is associated with an increase in the silica activity of the system, promoting the replacement of the Ni-poor serpentine by the Ni-enriched talc-like phase. These results have interesting implications in material science, as garnierites are natural analogs of Ni-bearing phyllosilicate-supported synthetic catalysts. Finally, SAED and HRTEM suggest that the Ni-bearing talc-like phase corresponds to a variety of talc with extra water, showing larger d(001) than talc (i.e., 9.2-9.7 angstrom), described as 'kerolite'-'pimelite' in clay mineral literature. |
Note: | Versió postprint del document publicat a: https://doi.org/10.2138/am-2016-5518 |
It is part of: | American Mineralogist, 2016, vol. 101, num. 6, p. 1460-1473 |
URI: | http://hdl.handle.net/2445/160531 |
Related resource: | https://doi.org/10.2138/am-2016-5518 |
ISSN: | 0003-004X |
Appears in Collections: | Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada) |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
675058.pdf | 4.08 MB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.