Extensive experimental investigations are conducted on Gypsum and Quartz specimens of different sizes. They are brought to a complete compression failure, showing two different failure modalities: (1) Very brittle loading drop for micro-crystalline Gypsum and Quartz; (2) Post-peak strain-softening behavior for macro-crystalline Gypsum. All the tested specimens emit acoustic and electromagnetic waves, and the single events are cumulated up to the peak load. On the other hand, neutron emissions are evident only for the largest specimens. The significant chemical composition changes occurring on the fracture surfaces are consistently explained by the assumption of Low-Energy Nuclear Reactions (LENR), both fusion and fission reactions. It is the first time that fusion reactions appear due to fracture, whereas fission reactions have already consistently explained the results related to iron-rich natural and artificial rocks.