Ni-sepiolite-falcondoite in garnierite mineralization from the Falcondo Ni-laterite deposit, Dominican Republic

New chemical and structural data on sepiolite-falcondoite in garnierite veins from the Falcondo Ni-laterite deposits, central Dominican Republic, are reported. Samples of Ni-sepiolitefalcondoite vary in colour from whitish green to green depending on the NiO content (wt.%) and the amount of silica p...

Descripción completa

Detalles Bibliográficos
Autores: Tauler, Esperança, Proenza, Joaquín A., Galí Medina, Salvador, Lewis , John F., Labrador Carrasco, Manuel, García Romero, Emilia, Súarez Barrios, Mercedes, Longo, Francisco, Bloise, Giovanni
Tipo de recurso: artículo
Fecha de publicación:2009
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/50683
Acceso en línea:https://hdl.handle.net/20.500.14352/50683
Access Level:acceso abierto
Palabra clave:549.6(729.3)
Ni-sepiolite
Falcondoite
Garnierite
Crystal chemistry
Falcondo
Ni-laterites
Dominican Republic
Mineralogía (Geología)
2506.11 Mineralogía
Descripción
Sumario:New chemical and structural data on sepiolite-falcondoite in garnierite veins from the Falcondo Ni-laterite deposits, central Dominican Republic, are reported. Samples of Ni-sepiolitefalcondoite vary in colour from whitish green to green depending on the NiO content (wt.%) and the amount of silica present. The texture is normally schistose and friable but samples with considerable quartz and/or amorphous silica are compact and hard. Back-scattered electron images indicate that the samples are composed of at least three generations of Ni-sepiolite-falcondoite. The extreme refined cell parameters for Ni-sepiolite-falcondoite vary from 13.400(2), 27.006(4), 5.273(1) A˚ to 13.340(3), 27.001(6), 5.267(1) A˚ (space group Pncn). As the Ni content increases there is a small reduction in the a parameter. Chemical compositions determined by electron probe microanalysis cover a large interval of the Ni-sepiolite-falcondoite solid solution (Fal3 and Fal77). Individual samples show a considerable range in composition with the widest range determined in one sample from 4.63 to 22.40 wt.% NiO.