Bituminous coal thin section slide. Bituminous coal and indeed all other varieties of coal are classed as organic sedimentary rocks. The bituminous variety contains between 60 and 80% carbon, the remainder is composed of residual water, air, hydrogen, and sulphur i.e. the volatiles. These thin sections exhibit more air pockets then their anthracite counterpart as to be expected being the less pure, more volatile rich variety. The slides are 30 microns thick and measure 46 x 27 mm in size and have a cover slip of the section along with a protective cardboard sleeve.
