  Layered and nanotubular systems that are metallic or graphitic are known to
exhibit unusual dispersive van der Waals (vdW) power laws under some
circumstances. In this letter we investigate the vdW power laws of bulk and
finite layered systems and their interactions with other layered systems and
atoms in the electromagnetically non-retarded case. The investigation reveals
substantial difference between `cleavage' and `exfoliation' of graphite and
metals where cleavage obeys a $C_2 D^{-2}$ vdW power law while exfoliation
obeys a $C_3 \log(D/D_0) D^{-3}$ law for graphitics and a $C_{5/2} D^{-5/2}$
law for layered metals. This leads to questions of relevance in the
interpretation of experimental results for these systems which have previously
assumed more trival differences. Furthermore we gather further insight into the
effect of scale on the vdW power laws of systems that simultaneously exhibit
macroscopic and nanoscopic dimensions. We show that, for metallic and graphitic
layered systems, the known "unusual" power laws can be reduced to standard or
near standard power laws when the effective scale of one or more dimension is
changed. This allows better identification of the systems for which the
commonly employed `sum of $C_6 D^{-6}$' type vdW methods might be valid such as
layered bulk to layered bulk and layered bulk to atom.
