Infrared and Raman Spectroscopic Characterization of the Borate Mineral Vonsenite

ABSTRACT

There are a large number of boron-containing minerals, of which vonsenite is one. Some discussion about the molecular structure of vonsenite exists in the literature. Whether water is involved in the structure is ill-determined. The molecular structure of vonsenite has been assessed by the combination of Raman and infrared spectroscopy. The Raman spectrum is characterized by two intense broad bands at 997 and 1059 cm⁻¹ assigned to the BO stretching vibrational mode. A series of Raman bands in the 1200–1500 cm⁻¹ spectral range are attributed to BO antisymmetric stretching modes and in-plane bending modes. The infrared spectrum shows complexity in this spectral range. No Raman spectrum of water in the OH stretching region could be obtained. The infrared spectrum shows a series of overlapping bands with bands identified at 3037, 3245, 3443, 3556, and 3614 cm⁻¹. It is important to understand the structure of vonsenite in order to form nanomaterials based on its structure. Vibrational spectroscopy enables a better understanding of the structure of vonsenite.

KEYWORDS:

• borate
• infrared spectroscopy
• ludwigite
• molecular structure
• Raman spectroscopy
• vonsenite