Mining there has been repeatedly considered. It hadn’t happened mainly due to environmental concerns and politics, not practicality. For example, back in 2021 a left leaning party won elections there and pledged to block mining projects immediately:
The same article mentions that even at that time, a partnership between an Australian company (whose biggest shareholder is a Chinese company) and a Chinese company had already spent $100 million on preparing for a mining project, at this place:
https://www.reuters.com/article/world/left-wing-party-wins-g...
The same article mentions that even at that time, a partnership between an Australian company (whose biggest shareholder is a Chinese company) and a Chinese company had already spent $100 million on preparing for a mining project, at this place:
https://en.wikipedia.org/wiki/Kvanefjeld
TLDR there has been a long history of outside countries trying to access rare earth minerals (and other things) in Greenland, but especially China.