text: Actually for your example, I would point out whale oil. 
  
  It is one of the best lubricants for machinery around, very hard to get today, but at one point we burned it for light. And while depleted the resource we got that from has actually being increasing (Slowly) because of the current lack of commercial harvesting of the resource.
  
  Look at oak. Makes great charcoal and a good warm heating fire, but it is much more valuable being made into furniture. Eventually our current preferred fuel, oil, will be replaced with something else, but only when a viable alternative makes economic sense.