The present work involves a synthesis and characterization of novel carbon phase from single wall carbon nanotubes (SWCNTs). The synthesis of this new material implicates extremely high-pressure process performed in the High-pressure spectroscopy laboratory at Lulea? University of Technology.Diamond anvil cell technology was used to expose SWCNTs to a non-hydrostatic pressure up to 1 Mbar. This technique allowed the in-situ monitoring by Raman spectroscopy of the pressure applied to the sample surface, by tracking at the same time the fluorescence and Raman signal of ruby and the diamond anvil respectively. It also allowed the in-situ characterization of phase transformation of the SWCNTs. It has been possible to observe evidence of deformation of the CNTs and to approximate the pressure of collapse of the CNTs, in good agreement to the previous works. Several studies have suggested that a phase transformation of the CNTs into a disordered carbon phase takes place, with outstanding mechanical properties when comparing to diamond for instance. In this study, the resulting material exhibited a Raman spectra typically found in disordered carbon phases. The results indicated a material most likely dominated it by an amorphous phase with the presence of an ordered phase as nanographene clusters. The final phase showed a direct dependence on the maximum pressure at which the region was exposed. Further analysis showed an increasing of the disorder related it to the pressure gradient in the diamond cullet. With the support previous disordered and amorphization studies, it was possible to approximate graphene cluster size, therefore to correlate it to the pressure applied. By comparison to well-known nanographene phases, we were able to predict mechanical properties, hardness around 30 GPa and Young`s modulus of 200 GPa were approximated. However, mechanical testing such as nanohardness is required in order to define these properties.