Bituminous cobbles collected from the Fossil Forest site (Geodetic Hills, Axel Heiberg Island, Canadian Arctic) have been subjected to petrographic and geochemical characterization. Transmitted light microscopy and pyrolytic analyses indicate that these samples are derived from algal biomass and are in most ways, generally comparable with other boghead coals and torbanites. However, fluorescence microscopy results in the surprising observation that these samples do not fluoresce under normal blue-light excitation conditions. Strong fluorescence is generally considered to be characteristic of alginites and Type I (and II) kerogens, and the absence of this property in these samples suggests that even petrographic analyses with blue-light excitation (fluorescence) may underestimate the occurrence of algal-derived materials in some samples. (c) 2006 Elsevier B.V. All rights reserved.