Anthracite is the hardest type of coal.
Anthracite is the hardest type of coal.
Anthracite
ANTHRACITE!
anthracite
Anthracite is the hardest type of coal.
Anthracite is the hardest type of coal.
Anthracite is the hardest type of coal.
Anthracite
ANTHRACITE!
anthracite
Lignite is the youngest and softest coal; bituminous is mid-grade coal, and anthracite is the hardest and hottest burning coal. Even brown coal.
Anthracite, the hardest coal, forms from the greatest pressure.
The name of the hardest solid is a diamond; it is the hardest object known to humankind.
Anthracite is metamorphosed bituminous coal, a coal with the highest percentage of carbon of the coal varieties.
Another name for bituminous coal is soft coal.
Particulate coal