Please use this identifier to cite or link to this item:
Title: Characterization of beryl (aquamarine variety) from pegmatites of Minas Gerais, Brazil.
Authors: Viana, Rúbia Ribeiro
Evangelista, Hanna Jordt
Costa, Geraldo Magela da
Stern, Willem B.
Keywords: Beryl
Channel constituents
Thermal expansion
Issue Date: 2002
Citation: VIANA, R. R. et al. Characterization of beryl (aquamarine variety) from pegmatites of Minas Gerais, Brazil. Physics and Chemistry of Minerals, v. 29, p. 668-679, 2002. Disponível em: <>. Acesso em: 20 de jun. 2017.
Abstract: Eight samples of the beryl variety aquamarine were selected from four pegmatites in the Governador Valadares and Arac¸uaı´ regions in northeastern Minas Gerais State, Brazil. These samples were fully characterized by chemical analysis, infrared and UV-visible spectroscopy, thermal analyses, and high-temperature X-ray diffraction (from room temperature up to 800 C). Several physical and chemical properties of beryl were found to depend on the amount of water and ions residing in the structural channels. The thermal expansion coefficients from room temperature to about 800 C are temperature-independent, with aa @ )3.2 · 10)6 C)1 and ac @ )8.7 · 10)6 C)1. The contraction of both a and c unit-cell parameters with increasing temperature and the shift of the infrared band centered at about 1200 cm)1 were tentatively ascribed to interactions between channel water and the silicate rings. The color of beryl seems to be dictated by the relative proportions of Fe3+ in the octahedral sites and of fe2+ in the channels. Thus, deep-blue samples have little Fe3+, whereas greener samples have more Fe3+ or less channel Fe2+.
ISSN: 1432-2021
Appears in Collections:DEGEO - Artigos de periódicos

Files in This Item:
File Description SizeFormat 
ARTIGO_CharacterizationBerylAquamarine.pdf420,2 kBAdobe PDFView/Open    Request a copy

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.