Interrelationship «structure-hardness-fusibility» for oxide crystals

The indistinct interrelationship between the mel-ting temperature (T m ), Mohs hardness (H s ), thermal con-ductivity (k), and structure of many oxide synthetic crys-tals, and minerals has been established more detail. It is shown that the external boundary of the full set {H s - T m } is res-tricted with 7-side polygon. These data has been useful at search of the most hardness and heat-conducting materials for optoelectronic devices.