Pearson Coal Petrography

Fingerprinting your coals, cokes, and carbons

Imaging Carbon Forms and Petroleum Coke

Our Bireflectance Imaging and Fingerprinting microscope systems can be used to determine the provenance of source feedstocks of Petroleum Cokes.


When mesophase spheres are present in unreacted, lower reflecting and bireflecting groundmass material in petroleum cokes, they are referred to as Calcined Cokes or Green PetCokes, and are confirmed chemically by elevated volatile contents.



Recently, we have imaged isotropic carbon fibers, which have the appearance of  a bird’s nest, or a pile of twigs. Although these are a surface phenomenon, they become the locus of spherulytic and pyrolytic carbon deposition.

Hairy Coke

Similar to findings by Honda (1988),  the coke fibers have an onion-like skin texture which is vapour phase deposited carbon, with the interior part of the fiber demonstrating an isotropic nature.  Below is an image of a single carbon fiber taken from the nest above, and masked, using our seven- coke type classification (refer to Pearson 2012).


The carbon fiber shown here in bireflectance color mode, displays an apparently radial deposition of the isotropic core.


This exploration of carbon microscopy is current active research, as we investigate areas for commercial application.