  Two-mode valence electron configuration of carbon atoms lays the foundation
of the unique two-mode amorphous state of the monoatomic carbon solid. From the
fundamentals of solid-state physics, sp$^3$ and sp$^2$ amorphous carbons are
two different amorphous species characterized by conceptually different
short-range orders, namely, groups of tetrahedrally bonded sp3 configured atoms
and size-restricted sp$^2$ graphene domains framed with heteroatom necklaces.
Molecular character of sp$^2$ amorphics is coherent with the reaction mechanism
of the solid amorphicity in due course of the forced fragmentation.
