Frost, Ray LeslieCipriano, Ricardo Augusto ScholzLópez, AndrésXi, YunfeiGranja, AmandaGobac, Željka ŽigovečkiLima, Rosa Malena Fernandes2014-12-142014-12-142013FROST, R. L. et al. Infrared and Raman spectroscopic characterization of the silicate mineral olmiite CaMn^2+[SiO3(OH)](OH) – implications for the molecular structure. Journal of Molecular Structure, v. 1053, p. 22-26, 2013. Disponível em: <http://www.sciencedirect.com/science/article/pii/S0022286013007278>. Acesso em: 07 out. 2014.0022-2860http://www.repositorio.ufop.br/handle/123456789/4169We have studied the mineral olmiite CaMn[SiO3(OH)](OH) which forms a series with its calcium analogue poldervaartite CaCa[SiO3(OH)](OH) using a range of techniques including scanning electron microscopy, thermogravimetric analysis, Raman and infrared spectroscopy. Chemical analysis shows the mineral is purê and contains only calcium and manganese in the formula. Thermogravimetric analysis proves the mineral decomposes at 502 °C with a mass loss of 8.8% compared with the theoretical mass loss of 8.737%. A strong Raman band at 853 cm^-1 is assigned to the SiO stretching vibration of the SiO3(OH) units. Two Raman bands at 914 and 953 cm^-1 are attributed to the antisymmetric vibrations. Two intense Raman bands observed at 3511 and 3550 cm^-1are assigned to the OH stretching vibration of the SiO3(OH) units. The observation of multiple OH bands supports the concept of the non-equivalence of the OH units. Vibrational spectroscopy enables a detailed assessment of the molecular structure of olmiite.en-USOlmiitePhosphateRaman spectroscopyInfrared spectroscopyArtigo publicado em periodicoO periódico Journal of Molecular Structure concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 3487250016396.https://doi.org/10.1016/j.molstruc.2013.08.038