Dark, heavy lump of coal
Keywords
coal,
fossil,
fuel,
energy,
black,
geology,
mineral,
rock,
earth,
mining,
carbon,
natural,
resource,
industry,
power,
fueling,
combustion,
extraction,
deposit,
blackness,
hard,
dense,
solid,
industrial,
heat,
energy production,
electricity,
environment,
pollution,
climate,
change,
emission,
sustainable,
alternative,
renewable,
geologic,
formation,
sedimentary,
layered,
rough,
texture,
anthracite,
bituminous