Relationship between the maximum and the random reflectance of vitrinite for coal from the Upper Silesian Coal Basin (Poland)

The relationship between the maximum and random reflectance of vitrinite, R-max and R-r, for Upper Silesian coal is represented by the equation: R-max = 1.090R(r) - 0.052. When the random reflectance is higher than 0.90%, the difference between R-max and R-r values becomes significant. R-max is a more precise rank indicator, the standard deviation is much smaller than the standard deviation of the random reflectance value, which is larger due to the optical anisotropy of vitrinite. (C) 2001 Elsevier Science Ltd. All rights reserved.