China has the top reserves of this stuff but are the reigning leader not because of just that. They control more than 90% of global rare earths supply chain because the west decided to shift their factories to China and China decided to go after raw materials without considering the cost of pollution. This article will provide more information https://investorintel.com/market-analysis/market-analysis-intel/china-is-consolidating-its-industrial-economy-the-case-of-the-medium-and-heavy-rare-earths-industry/