Interfacial properties have been measured, using surface pressure-area and surface potential-area isotherms at the air-water interface, for buckminsterfullerene, C60, pure and mixed with arachidic acid. The results show that C60 agglomerates and forms an irregular film at the air-water interface, even when mixed with a long-chain fatty acid. Vibrational properties were observed with inelastic electron tunneling spectroscopy (IETS) for a film of pure C60 prepared by the spinning technique. The assignment of frequencies for the 46 vibrational modes of C60 was accomplished.