Abstract: A method for the determination of the organic carbon content of raw mineral materials, e.g., raw rocks, sediments and the like, is disclosed which comprises pyrolyzing a sample of raw material which is previously crushed at a temperature of between 400.degree. and 1,000.degree. C, analyzing the pyrolysis gases by gas chromatography, and determining the benzene content of the pyrolysis gases. By determining the benzene content of pyrolysis products from raw materials with a known organic carbon content, the relationship between these two values at a given pyrolysis temperature is determined prior to the analysis of unknown material. An apparatus for effecting this determination method is also disclosed.