Antimony: The Metal Nobody Notices-Until America's Ammunition Supply Is at Risk

Highlights

• U.S. antimony net import reliance reached 91% in 2025, with China supplying 55% of antimony metal and oxide imports between 2021 and 2024.
• REEx co-founders visited the Perpetua Resources and Idaho National Laboratory antimony trisulfide pilot facility in July 2026, a key step toward domestic defense-grade production.
• The U.S. Army targets late-2028 for Stibnite raw antimony sulfide output, but Perpetua's own guidance points to 2029 commercial operations, leaving a critical Transition Vulnerability Window.
• China's leverage extends beyond mining to overseas ownership, concentrate purchasing, processing infrastructure and export licensing—geographic diversification alone does not equal supply independence.
• REEx's Five-Gate Supply-Chain Model evaluates upstream availability, ownership independence, midstream conversion, product qualification and commercial durability to separate genuine resilience from promotional narratives.