We measured the elastic modulus and fracture strength at the micro-level for various types of crystal generated by an MSMPR crystallizer. The attrition behavior was determined from the fracture energy and attrition coefficient, which were calculated from micro-hardness properties. The different values observed for each tested crystal size revealed that crystal size was an important factor in attrition behavior. Therefore, we could predict the amount of attrition through the fracture energy. Future work will involve applying the estimation method in a scaled-up suspension crystallizer. (c) 2006 Elsevier B.V. All rights reserved.