a carbide ceramic
A carbide ceramic joins a metal or silicon to carbon. The famous members are silicon carbide SiC (carborundum, the black grit on sandpaper and sharpening stones), boron carbide B4C (one of the hardest materials known, used in body armour), and tungsten carbide WC (the tip of a cutting tool or the ball in a ballpoint pen). Where oxides are the already-burned branch, carbides are the diamond-like branch, very hard and very covalent.
Carbon and silicon have similar, moderate electronegativities, so bonds like Si-C are largely covalent and directional, much like the bonds in diamond. That buys extreme hardness (SiC and B4C sit near the top of the hardness scale, just below diamond), very high stiffness, high thermal conductivity in the case of SiC (it can shed heat like a metal), and excellent refractoriness. Many carbides are also electrically conductive, unlike typical oxides.
SiC turns up as abrasives, brake discs, pump seals, high-power electronics, and mirrors for space telescopes; WC as the hard phase in cemented-carbide cutting tools (bonded with cobalt); B4C as armour and neutron shielding. The honest catch is oxidation: because carbides are not yet oxidised, in hot air they slowly react with oxygen. SiC is saved by forming a protective silica skin (passive oxidation) up to very high temperatures; less-protected carbides degrade, so carbides are often reserved for inert, reducing, or protected environments, the mirror image of the oxide trade-off.
The dark, glittering grit glued to sandpaper is silicon carbide (SiC): its covalent, diamond-like bonds make it hard enough to grind steel, and it conducts heat well enough to serve as a heat-spreader in high-power electronics.
Metal- or silicon-plus-carbon: covalent, extremely hard, stiff, refractory, but oxidisable in hot air.
Carbides are not pre-oxidised, so they can burn in hot air. SiC survives by growing a protective silica layer; this passive oxide skin is what lets it be used to about 1600 degrees C.