Athabasca bitumen separated from the associated mineral matter by Soxhlet extraction contains fine clay particles and inherent ash. Empirical relations have been developed to estimate the percentage of clay and inherent ash present in the asphaltene fraction which concentrates in large measure the mineral constituents present in the bitumen. The ash level, Y, of the asphaltenes is related to the weight per cent of clay, C t, by an expression of the form Y = 0.872C t + 0.582. The ash level of the asphaltene fraction is also correlated with the infrared absorbance, A, at 1032 cm -1 which gives an approximate empirical relation of the form A = 0.0648Y + 0.294. Greater accuracy at low ash levels can be achieved by measuring A at 1040 cm 1 above the base line drawn from 960 to 1140 cm -1 . This results in the equation A = 0.0709Y + 0.0124 when a standard KBr pellet thickness of 0.833 mm and concentration of 2 mg asphaltene per 300 mg KBr is used. X-ray diffraction used to characterize the clay minerals shows decreasing crystallinity as the particle size diminishes. The infrared absorbance of this mineral matter indicates decreasing intensity of the band at 2930 cm -1, associated with adsorbed and occluded organic matter, relative to the two characteristic clay bands at 3697 and 3620 cm -1 as the particle size decreases. Trace element analysis of the asphaltene inherent ash, by inductively coupled argon plasma, shows the major metallic constituents to be vanadium, nickel and iron with minor amounts of calcium, potassium, aluminium and sodium.