Hardness (MH) is calculated by means of the method of many-electron operator spinors as phase transition with formation of ‘orbital glass’. Indenter pressure $P_{J}$ overcomes (internal) connection forces $E_{el}$ (band, covalent et al.). ‘Orbital glass’ energy $E_{OG}$ is the largest in precious stones and metals $P_{MH} \approx E_{OG} \gg E_{el}$. Magnetic field $B^z$ under transition, side by side with deformation $u_{33}$, draws up segregation $L_{r} \parallel 0_{z}$, Galois group $G_{33}$. In large fields $B^z > B_{cr}$ domain walls $L^z_{r}$ degenerate into asymmetrical phases (amorphous carbon). These are defects of crystal diamond.