A method for making a boron carbide containing ceramic involves pyrolyzing a precursor having one or more monosubstituted decaboranyl groups and at least one substituting group containing carbon. The precursor may be molecular, for example comprising two decaboranyl groups linked by a single substituting group, or polymeric, in which case the decaboranyl groups are part of the pendant group of the polymer while a portion of the substituting group makes up the polymer backbone. In either case, the substituting group may be a hydrocarbon, in which case boron carbide may be formed. Alternatively, the substituting group may contain carbon and another ceramic forming element (i. e. , other than boron or carbon), such as silicon, nitrogen, or phosphorous, in which case a composite including boron carbide is formed. The precursors used in the present invention are relatively stable in air, allow access to both boron rich and carbon rich materials, and further allow for the formation of films, fibers, and nanostructured materials more easily than other precursors.