What's an example of a resource, raw material that has become scarce? I'm interested in the elasticity price demand that predicts that as a resource becomes more scarce, it gets more expensive. 

Regarding oil price this isn't clear. Is there an example of a resource that has nearly disappeared ? What was the evolution of its price ?
Some examples you might consider:


Fine art when the artist dies (this doesn't reduce the number of works by that artist, but does reduce the number of works that can be expected to exist in the future)
The electromagnetic spectrum - there are a bunch of interesting resources concerning auctions for space on the spectrum
Short .com domain names