The Bridge Between the Ideal and Real Mechanical Properties for Superhard Materials -- Thermodynamic and Kinetic Aspects of Spontaneus Crystallization of Diamond and Cubic Boron Nitride -- Strain-Induced Disorder and Phase Transformation in Hexagonal Boron Nitride under Quasi-Homogeneous Pressure up to 25 GPa: In-Situ X-Ray Study in a Rotational Diamond Anvil Cell -- Combining Hard with Soft Ma…