Intrinsic hardness of anthracene single crystals

The intrinsic hardness value of anthracene has been obtained by using the treatment of Westbrooke [Trans Am Soc Met, 45 (1953) 211]. It is observed that the hardness value is dependent on the mode of deforma tion. The intrinsic hardness value turns out to be 3.7 x 10(3) kg/mm(2) for slip system <(20(1)over bar)> [010] and 6.8 x 10(2) kg/mm(2) for slip system (100) [010]. At 320 K the hardness value is nearly the same.