A term which describes the morphology of carbonaceous mesophase which is formed in the isotropic pitch matrix. The spherical carbonaceous mesophase usually has a lamellar structure consisting of flat aromatic molecules arranged in parallel layers which are perpendicular to the sphere/isotropic phase interface. On coalescence, this spherical mesophase loses its characteristic morphology and is converted to the bulk mesophase.
PAC, 1995, 67, 473. 'Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)' on page 505 (https://doi.org/10.1351/pac199567030473)