Spectral signatures of infrared OH bands in pyroxenes from mantle xenoliths provide important information on water speciation in mantle lithospheres. We identified two characteristic types of spectral signatures in pyroxenes from mantle xenoliths: (a) Cpx and opx dominated by OH bands at 3595, 3517 cm-1 and 3571, 3517 cm-1, respectively. (b) Cpx and opx dominated by OH bands at 3635, 3445 cm-1 and 3602, 3417 cm-1, respectively. To understand the origin of these signatures and the nature of H-defects associated with them it is essential to isolate and characterize each specific bands that compose the spectra. We present a low-temperature polarized infrared analysis of end-member signatures of these pyroxenes and identify the characteristics of the individual bands that compose their specific patterns. Possible bands assignments are discussed as well as possible strategies to implement identification.