Brittleness Index of High-Rank Coal Reservoir and Its Influencing Factors in Mabidong Block, Qinshui Basin, China

Table 1

Coal-body structure division of a coal seam in the Mabidong block (refer to reference [21]).

Coal-body structure	Coal core shape	Coal core photograph	Description of coal core characteristics
Primary structure	Column, block		The band of coal lithotype and primary structure are clear, block structure, and hard.
Cataclastic structure	Column, block, coal broken		The band is visible, but the coal is intersected by exogenous fractures without clear displacement and is also block.
Granulated structure	Crushed, coal broken seriously		The primary band and block structure are damaged, and particle structure, small cracks in different directions developed, test by hand, it has a certain hardness and can be crushed into small fragments.