GPa. As shown in the Another work characterized the elastic properties of a pure siliceous faujasite, deriving a bulk modulus B0 of 38 GPa, the same of α-quartz, and the start of the amorphization at 2.2 GPa. CHA. The experimental characterization on the pure silica chabazite under pressure has found a phase transition at room temperature from the rhombohedral space group R3̅ m to the triclinic P1̅ occurring at 1.42 GPa. The triclinic symmetry of the cell is preserved up to 3.47 GPa, then the complete, irreversible amorphization is reached at 5.33 GPa.