The previous conditions are necessary to avoid gas cooling and, hence, fragmentation of the primordial gas cloud. Unable to fragment and form stars, the gas cloud undergoes a gravitational collapse of the entire structure, reaching extremely high matter density at its core, on the order of ~10 g/cm. At this density, the object undergoes a general relativistic instability, which leads to the formation of a black hole of a typical mass ~ 10 M ☉, and up to 1 million M ☉. The occurrence of the general relativistic instability, as well as the absence of the intermediate stellar phase, led to the denomination of direct collapse black hole. In other words, these objects collapse directly from the primordial gas cloud, not from a stellar progenitor as prescribed in standard black hole models.