Infrared and polarized Raman spectra of Na2B4O7.10H2O are recorded and analyzed. The vibrational assignments are made on the basis of vibrations due to BO4 and BO3 groups, water molecules, and (B)OH bonds. Three types of water molecules exist in the crystal, and the BO4 groups are considerably distorted. Band assignments are confirmed by deuterium substitution. A SERS spectrum recorded in a silver colloid shows three enhanced bands at 800, 480, and 464 cm-1. (C) 1994 Academic Press, Inc.