Why does China dominate the world market for processed rare earth minerals with a share of about 85%?

It is Western stupidity! Too much government overregulation and environmentalism prevents the processing of rare earth in Western countries.

One could also say Western countries offloaded the processing to China to satisfy green activists!

"... While China only controls about 30 percent of the rare earth minerals known to exist on the planet, they process about 85 percent of it. This is down from a peak of 97 percent a few years ago.

The reason why they are able to dominate is partially because of American bureaucracy and hypocrisy. Our bureaucracy creates mountains of red tape that must be navigated in order to get these elements out of the ground (or ocean) and into useable form, in large part due to environmental concerns. ..."

Breitbart Business Digest