Yep, but non-metal as well

I'm not 100% sure on the english definition but the greek root (we call them OPYKTA, pronounced as o-ree-ktah) definitely includes both, so the word itself also includes stuff like sulfur, coal, etc.

Coal is very big in N.Korea... yet total bitcoin mining, if calculated at 4k $ per BTC x 14 BTC per block (including fees) x 144 blocks per day x 365 blocks per year, is just 2.94 billion usd per year. If N. Korea had, say, even 10% of the global btc mining power, that's peanuts (=294 million usd) compared to their mineral wealth that is well into the trillion-dollar range, and doesn't require buying ASIC hardware from foreigners. It's stuff that they can get out of the ground with low-tech means. It's all bullshit stories and fake news floating around.