In our hydrothermal experiments using granite and artificial quartz, fracturing was found to be accelerated under a set of specific temperature and pressure conditions which we have termed hydrothermally derived fracturing (HDF). In addition, this phenomena was also observed to occur under natural conditions. In this paper we show examples of natural and experimental HDF. In a set of hydrothermal experiments, fractures were initiated by quartz fracturing, and fractures were enhanced at specific hydrothermal conditions compared to dry conditions. Occurrences of fracturing are inferred to be effected by solid-water interaction. The infrared spectra of OH stretching vibration of interfacial water were changed by environmental conditions such as temperature, pressure and substrate, which is considered to relate HDF phenomena.