For determination of the water content in clinopyroxene infrared (IR) absorbance spectra were collected by Fourier-transform IR spectroscopy in the wavenumber range 550–7500 cm-1 with a resolution of 2 cm. The spectra were recorded with unpolarized IR radiation (transmittance mode) using a square aperture of 40 x 40 to 100 x 100 µm² to restrict the lateral size of the probed sample volume. This was done in order to probe only clear, transparent crystal volumes free of any visible inclusions, cracks, or alteration products. Fourier-transform Infrared spectroscopy (FTIR), unpolarized, transmittance mode. Bruker Vertex 70 spectrometer with a Hyperion 3000 microscope and an MCT detector. Spectra were generated by averaging over 32 scans, wavenumber range: 550–7500 cm-1, resolution: 2 cm. Square aperture of 40x40 to 60x60 µm².