The effect of fluorination on various types of phyllosilicate minerals has been investigated. Two different fluorination techniques have been used: direct F-2 gas and cold radio frequency plasma involving c-C4F8 or O-2/CF4 mixtures. The modifications of the surface composition and properties have been followed mostly by x-ray photoelectron spectroscopy (XPS). Depending of the fluorination reagents, a reactive etching process involving M-F bonding occurs (direct F-2 gas; O-2-CF4 rf plasma) or a carbon fluoride deposition takes place (c-C4F8 rf plasma). In the case of F-2-gas treated minerals, Si 2p XPS signal accounts for the presence of fluorinated Si environments. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3328826]