Vickers hardness studies on (001) and (110) faces of DAST crystal

4-Dimethylamino-N-methyl 4-Stilbazolium Tosylate (DAST) crystals were prepared by the slope nucleation method. The Vickers hardness of DAST crystal was studied on (001) and (110) faces. It was found that the Vickers hardness increases with increasing load and the H-nu on (001) face is higher than that on (110) face. The values of Meyer's index number n and hardness were calculated from H-nu. The results showed that the DAST crystals belong to the soft material category.