Table 2: Diamond and nanodiamond size diagnostics based upon the C-H stretching vibrations in the 3.4 to 3.7 m spectral region.

Size range	Characteristic spectral features
>50 nm	Broad bands at 3.4 and 3.5 m with
	well-defined sub-structure bands at
	3.41, 3.43, 3.45, 3.50, 3.51 and 3.53 m.
	The 3.53 m band is particularly strong.
50-25 nm	Broad bands at 3.4 and 3.5 m with
	weak sub-structure bands at 3.41, 3.43,
	3.45, 3.50, 3.51 and 3.53 m. Note that
	the 3.53 m band now only appears as
	sub-structure.
25-5 nm	Broad bands at 3.4 and 3.5 m with a
	slight asymmetry due to very weak
	sub-bands in the red wings. There is
	a clear dip between the two bands.
<5 nm	Broad bands at 3.4 and 3.5 m with a
	hint of very weak sub-bands in the red
	wings. There is a less-pronounced dip
	between the two bands.