A material of carbon nanotubes and diamond bonded together. A method of producing carbon nanotubes and diamond covalently bonded together is disclosed with a substrate on which is deposited nanoparticles of a suitable catalyst on a surface of the substrate. A diamond seeding material is deposited on the surface of the substrate, and then the substrate is exposed to a hydrogen poor plasma for a time sufficient to grow carbon nanotubes and diamond covalently bonded together.