The comment about iron ore being infinite is interesting.
It all started in the Pilbara when Lang Hancock's aerial compass threw a wobbly, a lifetime ago. But iron ore was worth next to nothing then.
Fast forward a lifetime, and the price starts to rise. Exploration becomes viable, but there are many hurdles, remote extremely inhospitable (= expensive) location, Native Title minefield to negotiate, banks to convince, feasibility studies to finance. More and more iron ore deposits became viable, mountains of it literally.
The bottom line is that the amount of iron ore is a function of the price. At low prices only the most pure is worth developing, as the price rises lesser quality deposits become viable.
The amount of water in the ocean is not infinite, but it is for practical purposes. Iron ore is in the same boat, so to speak. At current prices it is for practical purposes in infinite supply..
