Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?
Absolutely not.
First of all, &quot;rare earth magnet ore&quot;, meaning the ores of metals like neodymium (Nd) and samarium (Sm), is not magnetic at all. It only becomes a magnet once you make a magnet out of it. For example, one such magnet is Nd2Fe14B  and it only becomes a magnet after neodymium is combined with iron and boron.
Naturally occuring neodymium ore is usually in the form of minerals such as bastnäsite (a rare earth carbonate) or monazite (rare earth phosphate) that are not magnetic.
It gets even worse!
Even if by some force of magic the rare earth ore would protect you from cosmic radiation, you now have two problems:

Most rare earth ore also has significant amounts of the radioactive thorium and uranium. You do not want to live in these areas, as any &quot;protection&quot; from cosmic radiation will be more than compensated for by the background radiation of the place you are now living in.
These are not nice places to live in. The three operating or recently operating rare earth extraction operations (aka mines) are in the desert. Bayan Obo in China, Mount Weld in Australia, and Mountain Pass in the United States.