Inspired by the Brazilian disk geometry we examine the utility of an edge cracked semicircular disk (ECSD) specimen for rapid assessment of fracture toughness of brittle materials using compressive loading. It is desirable to optimize the geometry towards a constant form factor F for evaluating KI. In this investigation photoelastic and finite element results for KI evaluation highlight the effect of loading modeled using a Hertzian. A Hertzian loading subtending 4° at the center leads to a surprisingly constant form factor of 1.36. This special case is further analyzed by applying uniform pressure over a chord for facilitating testing. © 2013 Elsevier Ltd.