Vibrational spectroscopy of the mineral meyerhofferite CaB3O3(OH)5 H2O - an assessment of the molecular structure.

Resumo
Meyerhofferite is a calcium hydrated borate mineral with ideal formula: CaB3O3(OH)5_H2O and occurs as white complex acicular to crude crystals with length up to _4 cm, in fibrous divergent, radiating aggregates or reticulated and is often found in sedimentary or lake-bed borate deposits. The Raman spectrum of meyerhofferite is dominated by intense sharp band at 880 cm_1 assigned to the symmetric stretching mode of trigonal boron. Broad Raman bands at 1046, 1110, 1135 and 1201 cm_1 are attributed to BOH in-plane bending modes. Raman bands in the 900–1000 cm_1 spectral region are assigned to the antisymmetric stretching of tetrahedral boron. Distinct OH stretching Raman bands are observed at 3400, 3483 and 3608 cm_1. The mineral meyerhofferite has a distinct Raman spectrum which is different from the spectrum of other borate minerals, making Raman spectroscopy a very useful tool for the detection of meyerhofferite in sedimentary and lake bed deposits.
Descrição
Palavras-chave
Raman spectroscopy, Borate, Meyerhofferite, Inyoite, Colemanite
Citação
FROST, R. L. et al. ibrational spectroscopy of the mineral meyerhofferite CaB3O3(OH)5 H2O - an assessment of the molecular structure. Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy, v. 114, p. 27-32, 2013. Disponível em: <http://www.sciencedirect.com/science/article/pii/S1386142513004976>. Acesso em: 07 out. 2014.