Fracture simulation of real-world materials is an exceptionally challenging problem due to complex material properties like anisotropic elasticity and the presence of material impurities. We present a graph-based finite element method to simulate dynamic fracture in anisotropic materials. We further enhance this model by developing a novel probabilistic damage mechanics for modelling materials with impurities using a random graph-based formulation. We demonstrate how this formulation can be used by artists for directing and controlling fracture. We simulate and render fractures for a diverse set of materials to demonstrate the potency and robustness of our methods.