Please use this identifier to cite or link to this item:
http://www.repositorio.cdtn.br:8080/jspui/handle/123456789/570
Title: | Infrared and chemical characterization of natural amethysts and prasiolites colored by irradiation |
Title of periodic: | Materials Research São Carlos |
metadata.dc.title.subtitlejournal: | Ibero-american Journal of Materials |
Authors: | Lameiras, Fernando Soares Nunes, Eduardo Henrique Martins Vasconcelos, Wander Luís |
Affiliation: | Centro de Desenvolvimento da Tecnologia Nuclear/CDTN, Belo Horizonte, MG, Brasil Lamil Lage Minérios Ltda, Pará de Minas, MG, Brasil Universidade Federal de Minas Gerais/UFMG, Belo Horizonte, MG, Brasil |
Issue Date: | 2009 |
Keywords: | Amethysts;prasiolite;minerals;irradiation;trace amounts;infrared spectra |
Abstract: | The infrared bands of amethyst and prasiolite samples from different origins were correlated to the trace elements contents. Amethysts have an iron content greater than 20 ppm and a low content of sodium and potassium. Prasiolites have an aluminum content greater than 120 ppm and a higher overall trace elements content, which accounts for a strong absorption between 3200 and 3600 cm-1. Colorless samples of quartz that become amethysts and prasiolites after irradiation have infrared spectra at room temperature with a broad band at 3441 cm-1 and a sharp band at 3595 cm-1. The broad band splits in several bands at low temperatures that are related to AlSi and FeSi. The color of amethysts and prasiolites are assigned to [AlSiO4/h+]0 and [FeSiO4/h+]0 centers formed by the exposure to ionizing irradiation and to the influence of lattice distortions due to the content of iron as a substitute for silicon and a high content of trace elements of large ionic radius like potassium. |
Access: | L |
Appears in Collections: | Artigo de periódico |
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.