polygranular graphite 

https://doi.org/10.1351/goldbook.P04731
A graphite material composed of grains which can be clearly distinguished by means of optical microscopy.
Note:
From the viewpoint of crystallinity, a polygranular graphite is always a polycrystalline graphite but not vice versa. Most industrial graphite materials are polygranular. Monogranular materials consist mostly of non-graphitic carbon, such materials are called monolithic or agranular carbons.
Source:
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 501 [Terms] [Paper]