Non-and medium-polar compounds were powdered and extracted from the surface of weathered stones with n-hexane, acetone or liquid carbon dioxide. The extracts were concentrated and analyzed by gas chromatography-mass spectroscopy. Acidic compounds were identified after methylation with diazomethane. The acidic fraction mainly consisted of fatty acids bearing 11 to 24 carbon atoms. In the non-methylated fractions long-chained hydrocarbons, nitrogen compounds, phthalic esters as well as carbonic acid ethyl esters could be identified. The total carbon (TC) as well as the total inorganic (TIC) and the organic carbon (TOC) content of the powdered surface samples were measured by colourimetry.