This is anthracite coal, No. 4 sort, from Pennsylvania. It is sold in one pound bags.
Anthracite coal, or hard coal, has the highest carbon content, the greatest hardness, and the fewest impurities.
This is "No. 4 coal". No. 4 is a measurement of size, not content. The standard sizing of No. 4 coal is 3/64 to 3/32 inches (1.19 to 2.38 millimeters). Some random pieces measured 0.31 inches (8 millimeters).
The No. 4 is fine coal that can be used for water filtration and waste water treatment.