Highlights

• Viridis Mining announces a significant 200-million-tonne maiden ore reserve at its Colossus rare earth project in Brazil
• Prefeasibility study suggests a pre-tax NPV of US$1.41B with competitive operating costs of US$6.20/kg TREO
• Potential 40-year mine life comes with inherent risks including:
  • Metallurgy
  • Permitting
  • Market volatility

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The West Australian splashed big headlines this week: Viridis Mining & Minerals (opens in a new tab) has outlined a 200-million-tonne maiden ore reserve at its Colossus rare earth project in Brazil—enough for a projected 40-year mine life. Numbers like these sound world-class. But do they hold up, and what should investors really take away?

The Rock-Solid Core

Some elements here are factual and significant:

• The reserve is JORC-compliant and derived from a measured and indicated resource base.
• Grades reported: 740 ppm magnetic rare earth oxides (MREO) and 2,640 ppm TREO, which are respectable for ionic clay deposits.
• A low strip ratio (0.45:1) and renewable-powered infrastructure in Poços de Caldas could indeed underpin competitive costs.
• Viridis recently raised $11.5 million and has a prefeasibility study (PFS) pegging pre-tax NPV at US$1.41B with operating costs of US$6.20/kg TREO.

These details anchor Colossus as a credible, advancing project.

The Glitter: Where Optimism Shines Brightest

The article leans into superlatives: “world-class,” “tier-one,” “unmatched economics.” While the numbers are strong, the PFS is still based on assumptions—including a $90/kg NdPr price case. That’s below the U.S. DoD floor of $110/kg but still subject to volatility. Also, the claimed 40-year mine life hinges on steady 5Mtpa production, yet execution risks—metallurgy, permitting, environmental opposition—are only briefly acknowledged.

The Blind Spots: Questions Investors Should Ask

Several crucial details are glossed over:

• What are the projected recovery rates from ionic clay? These can make or break economics.
• How does Brazil’s regulatory and community environment affect timelines?
• Will Viridis secure offtake partners in a crowded field where Lynas, MP Materials, and Arafura already have geopolitical backing?
• With shares reportedly quadrupling in three months, how much of this story is already priced in?

Verdict: A Colossus, With Caveats

Viridis has delivered a legitimate milestone reserve that strengthens its standing in the rare earth space. But the reporting crosses into boosterism, presenting upside with little scrutiny of risk. For Rare Earth Exchanges readers, the playbook is simple: acknowledge the achievement, but keep a close eye on feasibility studies, recovery results, and the slow grind of permitting before treating Colossus as a sure bet.

Source: Andrew Todd, The West Australian (opens in a new tab), Aug. 20, 2025

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