  In this paper we pursue the natural consequences of the structure of
nanodiamonds and their surface relaxation and reconstruction to surfaces
exhibiting sp2 carbon atoms. We show that in the interstellar radiation field
nanodiamonds can be stochastically heated to temperatures as high as 1000 K and
give rise to discrete emission bands associated with the surface structures. We
therefore speculate that nanodiamonds can make a significant contribution
towards the 3-15 micron unidentified mid-infrared emission bands.
