Scientific literature and industrial processing methods demonstrate that coal and other carbon-rich organic precursors can be utilized to synthesize nanodiamonds and other advanced carbon materials.
The retrieved papers include recent reviews on coal-based nanocarbon materials explicitly discussing the synthesis of nanodiamonds from coal as an abundant carbon feedstock. Natural mantle-derived diamonds form from carbon in the Earth's mantle rather than fossilized coal (which is a crustal rock formed from ancient land plants), but technologically and experimentally, diamonds can indeed be derived from coal precursors. Therefore, the claim is supported by the literature on coal-derived nanodiamond synthesis.