Combining vitrinite reflectance (VR) and fluorescence alteration of multiple macerals (FAMM) analyses provide insights into the chemical nature of vitrinites (i.e., perhydrous vs. orthohydrous vs. subhydrous compositions) in Permian Gondwana coals of the Parana Basin, Brazil. The FAMM-derived equivalent VR (EqVR) values and relationships with VR can be determined according to calibration curves based largely on Permian Gondwana coals of eastern Australia. The analytical results indicate that vitrinites in the Parana Basin coals studied generally range from orthohydrous to perhydrous, with interpreted VR suppression ranging up to similar to 0.2% absolute for the most perhydrous case. The EqVR values of the Santa Catarina coals. which range from about 0.85% to 0.95% differ from VR values by about 0.10-0.15% absolute, potentially having significant implications on coal utilization. The causes of vitrinite reflectance suppression in the Parana Basin coals are as yet poorly understood, but are likely to be related to a combination of factors. (C) 2004 Elsevier B.V. All rights reserved.