Synthetic Question, page-6

Morphology is a limiting factor (flake) as well as OAN, flake thickness (Lc) when trying to replace primary synthetic powders...primary synthetic powder morphologies can be bulky, irregular spheroid, potato shaped, elongated, flake, and high surface area (>200 m2/g). Other than spheriodisation, natural flake graphite is limited mainly by morphology.

They both can exceed purities of 99.95%.