ANTHRACITE COAL
Anthracite coal is the highest-rank coal. It forms by very low-
to low-grade metamorphism of bituminous coal. Anthracite is always black-colored,
with a glassy texture, and is harder & heavier than the other coals (although
it is still relatively soft & lightweight).
Unlike lignite and bituminous coal, anthracite is not sooty to the
touch. Anthracite burns hotter than other coal types, due to its high
carbon content (about 90% C). It also is the cleanest-burning of all the
coals.
Anthracite is the rarest variety of coal. The highest concentration of this rock is in Pennsylvanian-aged
anthracite coal fields in eastern Pennsylvania, USA.
Anthracite coal (3.9 cm across)