Tantalizing information about a possible existence of diamond stars has recently refocused attention of the scientific community on the basic properties of carbon-rich planets and stars. Since the carbon-rich star types are known for a usual presence of oxygen, it is not clear how carbon and oxygen can co-exist under extreme PT-conditions at a C/O < 1 atomic ratio. Therefore, the significance of the fact that the “star” PT-conditions (7000–13,000 K, 40 GPa) have been reached and sustained for a relatively long period of time in the oxygen-rich medium of the continuously laser heated diamond anvil cell, resulting in an optically transparent carbon glass (diamond-like glass) and, subsequently, oxygen-rich solid carbon synthesis, is hard to overestimate. Moreover, our results suggest that pure carbon can co-exist with oxygen under the extreme PT-conditions and have potential to open up a new technological way for production of novel super-refractory alloys and materials.