Allotropes of carbon
The allotropes of carbon are the different molecular configurations (allotropes) that pure carbon can take.
These allotropes include:
- amorphous carbon
- carbon nanofoam (discovered in 1997)
- carbon nanotube
- diamond
- fullerene
- graphite
- lonsdaleite
- ceraphite
The system of carbon allotropes spans a range of extremes.
Between diamond and graphite:
- Diamond is hardest mineral known to man, but graphite is one of the softest.
- Diamond is the ultimate abrasive, but graphite is a very good lubricant.
- Diamond is an excellent electrical insulator, but graphite is a conductor of electricity.
- Diamond is usually transparent, but graphite is opaque.
- Diamond crystallizes in the isometric system but graphite crystallizes in the hexagonal system.
Between amorphous carbon and nanotubes:
- Amorphous carbon is among the easiest materials to synthesize, but carbon nanotubes are extremely expensive to make.
- Amorphous carbon is completely isotropic, but carbon nanotubes are among the most anisotropic materials ever produced.