  Large variety of structure and chemical-composition of reduced graphene oxide
(RGO) is explained from a quantum-chemical standpoint. The related molecular
theory of graphene oxide, supported by large experience gained by the modern
graphene science, has led the foundation of the concept of a multi-stage
graphene oxide reduction. This microscopic approach has found a definite
confirmation when analyzing the available empirical data concerning both
synthetic and natural RGO products, the latter in view of shungite carbon,
suggesting the atomic-microscopic model for its structure.
