A case study in how the value of resources can change:
During the early 1800s aluminum was considered the most valuable metal in the world. This is why the capstone to the Washington Monument is made from aluminum, and also why Napoléon III himself threw a banquet for the king of Siam where the honored guests were given aluminum utensils, while the others had to make do with gold.
The price was high because aluminum was abundant but difficult to isolate. In 1886, two chemists figured out how to do it on the cheap:
Suddenly everyone on the planet had access to ridiculous amounts of cheap, light, pliable metal. Today aluminum is cheap, ubiquitous, and used with a throwaway mind-set. The point is this: when seen through the lens of technology, few resources are truly scarce; they’re mainly inaccessible.
(Image by Flickr user pasukaru76)