Camphene has been studied over ranges of pressure up to 9.5 GPa and temperature up to 1300 degrees C by in situ resist-volumetric, x-ray diffraction, and Raman scattering measurements as well as by postcompression analyses on retrieved samples, in the solid state, polymerized and amorphous phases appeared. The melting temperature was found to increase with increasing pressure and the melting line showed a small deflection at about 4 GPa, which was attributed to a triple point among the two solid phases and the Liquid. Another amorphous phase was retrieved from a region right above the melting line. Heat treatment at temperatures beyond the melting line by about 200 degrees C and higher yielded turbostratic and graphitic carbons.