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The introduction of mechanized tunneling with full face boring machines necessitates a better understanding of mechanical and petrographic characteristics of rocks. Evaluating the abrasiveness and drillability of rock, are prerequisites for choosing suitable boring instruments and machines. Compressive strength, hardness and abrasiveness are among parameters currently tested in this respect. Unfortunately the petrographic characteristics of rock, such as texture, are rarely considered. In this paper, the relation between the cerchar abrasiveness Index (CAI) and texture coefficient of rock is studied. The results of tests on samples of five groups of building stones of Iran show a weak correlation between CAI and texture coefficient, whereas a good correlation exists between the average of CAI and the average of texture coefficient of different rock groups