Abstract: A process is described for the production of dense metastable phases of carbon which have characteristics similar to diamond. Particulates of the metastable carbon are produced by reacting silicon carbide or a silicon carbide precursor, such as a silane or silicon metal, with a fluorocarbon, such as carbon tetrafluoride at a temperature greater than about 800.degree. C. A preferred range is from about 900.degree. C. to 1200.degree. C. The reaction may be carried out in a high voltage electrical diacharge, or other plasma, or in a furnace. The presence of a "promoter" metal, such as nickel and iron, increases the reaction rate and the quantity of the metastable carbon phases. Relatively large quantities of these diamond-like particulates are produced, and their properties are such as to make them useful for many of the same applications for which commercial diamonds are utilized. They are also useful in numerous high temperature applications.