Uso da técnica de EDXRF na análise de gemas semi preciosas brasileiras

• Autor(a) principal: Rezier, Ayxa Nara de Souza
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8041
• topic: Fluorescence; XRF; Gems; X-Ray; Characterization; Fluorescência; XRF; Raios X; Caracterização; Pedras preciosas; Gemas (Mineralogia); CNPQ::ENGENHARIAS::ENGENHARIA NUCLEAR::APLICACOES DE RADIOISOTOPOS

Brazil is one of the largest and most important producers of gemstones on the planet, besides being distinguished by the quality and gemological variety. It has a wide and diversified production scenario covering mainly the foreign market, with the main consumer sectors being jewelery and the stoning industry, as well as a wide range of use in the electronics, steel, electrical, optics, instrumentation, handicrafts and agriculture industries. With the technological advance, mineralogical studies and research are extremely important for the understanding of physicochemical properties, identification and chemical and structural characterization of gemstones, since the use of gemstones in industry is a function of their elemental composition. In the developed project, elemental characterizations were performed in samples of some Brazilian gems using the Energy Dispersion X-Ray Fluorescence technique (EDXRF). The qualitative determination of elements had as main objective to analyze and verify possible presence of elements and impurities that are not part of the elemental composition belonging to the class of silicates and carbonates. The analyzes were performed on two different portable devices, the Amptek mini mini-XRF and the Bruker AR ARTAX 200, with data acquisition and analysis programs from these manufacturers. The minerals analyzed were: Amethyst, Orange Calcite, Onyx, Jade, Citrine, Colorless Quartz, Milky Quartz, Blue Quartz, Green Quartz and Pink Quartz. The presence of metallic ions, in particular transition metals such as Ti, Cr, Mn, Fe, Co, Ni and Cu were verified. The possible reasons for the existence of these ions are discussed in the paper. The data of elemental analyzes by EDXRF indicate coherence in the elemental compositions obtained with the two portable systems of XRF and it is observed that both present efficiency in relation to the elements analyzed, indicating that the technique can be used to assist in the development of mineralogical studies.