Lithium can be obtained from plain old seawater. The issue is that the concentration per liter is low so it takes a lot of seawater to obtain useful amounts of

Lithium can be obtained from plain old seawater. The issue is that the concentration per liter is low so it takes a lot of seawater to obtain useful amounts of lithium -- it concentrates out just like any other salt, and as we know seawater is saltwater. But these processes are getting more efficient. And you can also recover other salts from seawater that may also be commercially useful. This is a planetary scale resource that can be "mined" from just about any coastline anywhere in the world.