Evidence for semiconducting behavior with a narrow band gap of Bernal   graphite
  We have studied the resistivity of a large number of highly oriented graphite samples with areas ranging from several mm$^2$ to a few $\mu$m$^2$ and thickness from $\sim 10 $nm to several tens of micrometers. The measured resistance can be explained by the parallel contribution of semiconducting graphene layers with low carrier density $< 10^9$ cm$^{-2}$ and the one from metallic-like internal interfaces. The results indicate that ideal graphite with Bernal stacking structure is a narrow-gap semiconductor with an energy gap $E_g \sim 40 $meV. 
N. Garc\'ia, P. Esquinazi, J. Barzola-Quiquia, S. Dusari
cond-mat.mtrl-sci cond-mat.supr-con