Highlights

• Stibnite Mine in Idaho represents a strategic restart of a critical minerals site with potential to supply 35% of U.S. antimony needs.
• The Pentagon views the mine as a key component in reducing dependence on foreign (particularly Chinese) critical mineral supply chains.
• Despite progress, the project faces significant challenges in production, processing, and infrastructure development.

---

The ribbon-cutting at Idaho’s Stibnite Mine was presented as nothing short of a national security milestone. Major General John T. Reim (opens in a new tab) declared it “one step closer to establishing a complete domestic supply chain” as Perpetua Resources reopens a site that once supplied 90% of U.S. military antimony needs during World War II. After eight years of permitting delays and $400 million in investment, the Pentagon is touting Stibnite as a secure domestic link in its “Ground-to-Round” munitions strategy.

A focus on a critical mineral, not an actual rare earth element/metal.

Gold-stibnite restoration in Idaho

What’s Solid Ground

The facts align: Stibnite holds the largest identified U.S. reserve of antimony—estimated at 149 million pounds, alongside 4.8 million ounces of gold and 6.4 million ounces of silver. Antimony is critical for hardened munitions, night vision, explosives, and a suite of defense applications. The Pentagon has every reason to reduce its dependence on imports, most of which today flow through China. The timing, too, is not coincidental—China’s export halts in 2024 and 2025 exposed just how fragile America’s supply chains remain.

Where the Narrative Overreaches

A recent Forbes piece frames Stibnite’s restart as if it alone could transform U.S. critical minerals security. That’s aspirational at best. Even at full tilt, the mine is expected to meet only about 35% of U.S. antimony needs. The remaining two-thirds will still come from abroad, and refining bottlenecks remain unaddressed. Moreover, the Pentagon’s celebratory rhetoric glosses over execution risks: posting financial assurance bonds, scaling operations, and ensuring downstream processing capacity in the U.S. are hurdles yet to be cleared.

The Rare Earths Angle That Matters

For investors, the takeaway is not that America suddenly solved its dependence problem—it hasn’t. Rather, Stibnite represents the first visible crack in the decades-long reliance on adversarial supply chains. The real questions remain unanswered: How quickly can Perpetua ramp production? Where will the antimony be processed? Can the U.S. build mine-to-munitions infrastructure without repeating past cycles of political neglect and permitting paralysis?

Final Word

Stibnite’s reopening is progress, but it is not a victory. The Pentagon has reclaimed a piece of industrial ground. Yet, the broader war for mineral independence will be decided by execution, capital discipline, and whether America can build not just mines—but magnets, alloys, and finished defense systems—on its own soil.

The Company

Perpetua Resources (opens in a new tab) (NASDAQ/TSX: PPTA) is advancing the Stibnite Gold Project in Idaho as a dual-purpose, “gold + antimony” operation wrapped in a site-restoration plan. The company positions Stibnite as one of the largest independent U.S. open-pit gold projects with 4.8 Moz Proven & Probable reserves (FS 2020; TRS 2021) and the only identified U.S. reserve of antimony—a Defense-critical mineral used in munitions and energy applications.

Financially, Perpetua highlights low projected costs (AISC LOM ~$756/oz with antimony by-product credits), strong early-years output (avg. 463 koz Au in yrs 1–4), and meaningful upside if antimony prices remain elevated. The project is framed as a national-interest asset: >$80M in DoD awards since 2022, designation as a White House “priority project,” and a formal U.S. EXIM financing application up to $2.0B alongside approximately $459M equity and planned royalty/stream plus a financial-assurance guarantee. Engineering is ~50% complete across major scopes, key federal permits were received in 2025, early works are planned for fall 2025, debt close is targeted for 2026, and commercial operations are aimed for 2029. The operating flowsheet includes flotation, POX, and gold leach, with antimony concentrate production; the plan also funds major legacy remediation (tailings rehandling, water quality improvements, river/fish passage restoration).

Risks are explicit and largely forward-looking: the EXIM LOI is non-binding and conditional; royalty/stream and financial-assurance negotiations remain in progress; initial capex is high (~$2.2B net, Q4-2024 basis); timelines rely on agency schedules and financing close; and model economics depend on commodity prices (consensus case: Au $2,100/oz; Sb $10/lb; Ag $27/oz). Technical disclosure cautions note differences between NI 43-101 and SEC Subpart 1300 classifications (measured→indicated; proven→probable) and that resources aren’t reserves.

Execution hinges on ramping construction, securing downstream antimony processing, sustaining cost discipline, and delivering promised environmental outcomes (10+ years of post-ops closure, ~25 years water treatment). With a supportive shareholder base (Paulson lead) and a management/technical team seasoned in U.S. permitting and mega-project delivery, Perpetua markets Stibnite as “responsible mining meets strategic supply”—but with financing, schedule, and market sensitivities that investors should weigh carefully.

Citation: David Blackmon, Forbes, “Pentagon Hails Restart Of Critical Minerals Mine In Idaho,” Sept. 21, 2025.

©!-- /wp:paragraph -->