Anthracite vs Bituminous coal

Anthracite is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest calorific content of all types of coal except for graphite.

Bituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal but of poorer quality than anthracite. Formation is usually the result of high pressure being exerted on lignite. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. 

Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning "light", and generally implies radiance, gloss, or brilliance.



Further reading:

Art of mantjfactttring bricks and tile

J Wood - US Patent 97, 1829

925

Determination of the apparent ratio of quaternary to tertiary aromatic carbon atoms in an anthracite coal by 13 C-1 H dipolar dephasing nmr

PDB Murphy, TJ Cassady, BC Gerstein - Fuel, 1982

90

Anthracite coal and the beginnings of the industrial revolution in the United States

AD Chandler - Business History Review, 1972

116

[PDF] jstor.org