• Comprehensive review identifies 45 drill holes with intercepts >2m at 0.20% Rb2O
• Notable high-grade intercepts include 5.8m @ 0.50% Rb2O and 5.5m @ 0.48% Rb2O
• Adds high-value rubidium to existing lithium resource, elevating Beecher to a multi-commodity critical minerals project

IRIS Metals Ltd has announced exceptional rubidium assay results from its 2023 and 2024 drilling programs at the Beecher Project in the Black Hills of South Dakota, USA. A comprehensive review of 117 drill holes identified 45 drill holes with intercepts exceeding 2 metres at greater than 0.20% Rb2O, including a standout intercept of 5.8 metres at 0.50% Rb2O. The addition of high-grade rubidium to Beecher's existing lithium resource elevates the project to a true multi-commodity critical minerals asset, reinforcing IRIS' position as a leading developer of a premier domestic critical minerals hub in the United States. IRIS plans to incorporate a maiden rubidium mineral resource in the upcoming Beecher Project Mineral Resource Estimate update, targeted for late Q1 - early Q2 2026. These rubidium intercepts position Beecher among the highest-grade rubidium deposits in the world, comparable to other significant global deposits. The Beecher Project benefits from an existing mining licence and proximity to excellent infrastructure in a mining-friendly jurisdiction, positioning IRIS to capture a meaningful share of the Western world's rubidium supply.

IRIS expects to hold the only declared rubidium Mineral Resource Estimates in the United States upon release of the updated Beecher and Tin Mountain MREs, planned for late Q1 - early Q2 2026.

IRIS is advancing an update of the 2025 Mineral Resource Estimate for Beecher, building on the 2025 lithium-only MRE for the Longview pegmatite. The updated MRE will include all three pegmatites at the Beecher Project, for both lithium and rubidium. A maiden MRE for Tin Mountain, also covering lithium and rubidium, is planned for the same timeframe.