Costa, Geraldo Magela daPolli, Gabriel de OliveiraKahwage, Márcio A.Grave, Eddy DeSabioni, Antônio Claret SoaresMendes, Julio Cesar2017-03-082017-03-082006COSTA, G. M. da et al. The effect of thermal treatment on the 57Fe Mössbauer spectrum of beryl. Physics and Chemistry of Minerals, v. 33, n. 3, p. 161-166, maio 2006. Disponível em: <https://link.springer.com/article/10.1007%2Fs00269-006-0064-3>. Acesso em: 08 mar. 2017.1432-2021http://www.repositorio.ufop.br/handle/123456789/7331Mo¨ssbauer spectra (MS) of blue, green and yellow beryl (ideally Be3Al2Si6O18) containing approximately 1% of iron were obtained at 295 and 500 K. Room temperature (RT) spectra of both blue and green samples showed the presence of an asymmetric Fe2+ doublet (DEQ 2.7 mm/s, d 1.1 mm/s), with a very broad low-velocity peak. There is no clear evidence for the presence of a ferric component. The MS of the yellow sample at RT consists of an intense central absorption with parameters typical for Fe3+ (DEQ 0.4 mm/s, d 0.29 mm/s), plus an apparently symmetrical Fe2+ doublet. This sample acquires a lightblue shade upon heating in air at about 620 K. Thermal treatments at high temperatures caused no significant changes in the MS, but the green and yellow beryl acquire a blue colour. All these results are interpreted in relation to the existence of channel water and the distribution of iron among the available crystallographic sites.en-USrestritoBerylThermal treatmentMössbauer spectroscopyArtigo publicado em periodicohttps://link.springer.com/article/10.1007%2Fs00269-006-0064-3https://doi.org/10.1007/s00269-006-0064-3