The carbonaceous materials in palaeoproterozoic Soanlahty formation have been studied by Raman microprobe spectroscopy and X-ray Difractometry. In the rocks metamorphosed from green schist to epidote-amphibolite facies carbonaceous material is defined as graphite with different degree of structural ordering. It is shown, that fine graphite rocks (metamorphosed sapropelites and oil shales) are the most heterogenic in terms of content of triperiodic structure and interspace defects.