bitcoin
black
charcoal
coal
deposit
earth
economic
emission
energy
extraction
fossil
fuel
gemstone
geological
heat
high
industry
interest
iron
making
material
mine
miner
mineral
mineralize
mining
money
oil shale
orebody
package
pickax
pickaxe
piece
power
production
purification
quality
resource
rock
silhouette
station
stone
tool
valuable
work