Abstract

AGOSTINHO, L. C. L.  and  NASCIMENTO, L.. Estudo das Propriedades Físicas e Químicas das Turmalinas Elbaíta Verde e Dravita Preta por Espectroscopia Fotoacústica. C.Tecn. Mat. [online]. 2010, vol.22, n.3-4, pp.71-75. ISSN 0870-8312.

The tourmaline group is one of the most complex groups of minerals in the large number of chemical elements regarding structure. Its large chemical variation results from the ease with which the metal ions present in their atomic sites contribute strongly to the wide variety of colors. This study is focused on the main characteristics of the chemical and physical properties of tourmaline, which are related by a crystallographic model of the mineral and ionic species in these samples. Spectral identification of two tourmalines (elbaite  green and dravite black) was carried out by Photoacoustic Spectroscopy . This allowed  the characterization of several centers of colors that cause the emission spectrum in the ultraviolet and visible, due to atomic interactions between ferrous and ferric ions that determine the prevalence associated or not with other ionic species of other chemical elements present in these tourmalines.

Keywords : Tourmaline; Ionic Species; Photoacoustic Spectroscopy.

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