Beryllium oxide as a ceramic material shows good thermal conductivity combined with high electrical resistivity. Therefore it is used among other things in electronics for contacting semiconductors for heat transfer, with the production of spark plugs as well as for melting crucibles. Because beryllium oxide is a toxic substance its use is however very limited, so that boron nitride can be considered as an alternative because of its likewise good heat conductivity combined with the same good electrical insulation characteristics.