Infrared reflectance of single-crystal jarandolite, CaB3O4(OH)3

Abstract

Polarized far- and mid-infrared reflectance spectra were measured at room temperature for the new mineral species jarandolite, CaB3O4(OH)(3), for the two principal directions. Thirty three vibration modes for (E) over right arrow parallel to(c) over right arrowc and 32 for (E) over right arrow perpendicular to(c) over right arrow were observed and analysed numerically. Symmetry analysis predicts 41 (E) over right arrow parallel to(c) over right arrow and 40 (E) over right arrow perpendicular to(c) over right arrow vibration modes that include lattice and O-H modes. Mode assignment was made based on the structure of jarandolite. The values of the mode frequencies (omega(TO)), the damping factors (gamma) and the oscillator strength (S) of each oscillator were obtained by fitting to a Lorentz model.