Plate P10. Coal and shaly coal-cork cells and suberinite. 3. T5818; Hole 1109D; 969.89 mbsf. Strongly fluorescing layer that appears to represent suberinite, although in general appearance it is similar to a sporangium. Polishing hardness is relatively high (reflected light; field width = 0.22 mm; mean vitrinite reflectance = 0.28% for sample).