african
black
blue
brown
building
climate change
coal
commodity
conveyor belt
copper
dirty
equipment
excavate
excavator
frame
gear
global warming
gold
head
headgear
hoist
industrial
industry
iron
metal
mine
mining industry
ore
platinum
platinum ore
purple
rays
rocks
shaft
silhouette
silo
silver
sky
steel
storage
structure
sunrise
sunset
tower
track
transport
work
yellow