I just learned that they are called rare earth elements, or REEs

I did some research and learned that Greenland actually has some successful mining operations underway, typically in the parts that are not under 2000 to 3,000 m of ice, so that's only 20% of Greenland, typically in the coastal areas. The big yield? Ruby's, interestingly enough.

Something I just connected though that makes sense is that Trump is making moves against China with his Panama canal comments, talking about how control over the canal must stay with Panama instead of being given to China. China is also reportedly sniffing around Greenland as well looking for mining opportunities so there is that.