Q-carbon is harder than diamond, incredibly simple to make. It's ferromagnetic, ... which are basically just areas of the Q-carbon which did fuse into the perfect diamond lattice structure.

Specifically, defects in the lattice structure of diamond, called nitrogen-vacancy (NV) centres, have been used as sensors or, more precisely, magnetometers to detect single nuclear spins at room ...

Both diamond and graphite are made entirely out of carbon, as is the more recently discovered buckminsterfullerene (a discrete soccer-ball-shaped molecule containing carbon 60 atoms).