Answer: anthracite

AnswerCrossword Clue
ANTHRACITE

Black diamonds

ANTHRACITE

Product of the Keystone State.

ANTHRACITE

Hard, lustrous coal

ANTHRACITE
Petrified product of Pa.
ANTHRACITE
Mineral with high carbon content
ANTHRACITEStone coal
ANTHRACITEHard natural coal