Multi-particle crushing tests were carried out using different particle configurations to investigate the effects of the coordination number on the failure stress of a single particle. Coarse grains of quartz and calcium-carbonate sands were tested, having sizes between 1 and 2.6 mm. The Weibull theory was applied to calculate the probability of surviving grain splitting. The failure stresses obtained for coordination numbers of four and six showed significant differences compared to a traditional single-particle crushing test. A high-speed camera was used to capture the failure mechanisms of the grains. Quartz grains failed in a brittle and sudden manner, whereas the carbonate particles failed in a more ductile way, regardless of the particle asperities. © 2015 Taylor & Francis Group.