August 18, 2026
BEAVERHEAD COUNTY, MONTANA — Mithril Mining Corp., a U.S. and veteran-owned critical minerals exploration and development company, today announced preliminary findings from a comprehensive geological and geochemical site investigation at the historic Calvert Tungsten Mine.
Conducted in collaboration with Utah State University (USU) Geosciences between May 22nd and May 26th, 2026, the investigation was led by Dr. Katherine Potter and a team of undergraduate students. The team characterized mined rock, collected fine-grained (<2 mm) material and rock samples, and gathered field and laboratory geochemical measurements using an Evident Vanta Max portable X-Ray fluorescence (pXRF) analyzer. The final report provides preliminary estimates of tungsten ore grade and highlights promising rare earth element (REE) potential across multiple priority sampling zones.
“The data provided by the Utah State University Geosciences team gives us a highly detailed look into the surface material and geological potential at the Calvert Mine,” said Taylor Sulik, CEO of Mithril Mining Corp. “The strong tungsten grades and the potential for economic rare earth element concentrations reinforce our commitment to advancing this critical domestic asset.”
“The Calvert Mine site investigation has provided USU undergraduate students with an opportunity to apply their coursework and develop professional skills in critical mineral exploration and evaluation,” said Dr. Katie Potter, P.G., Professional Practice Assistant Professor and GeoProfessional Program Director in the Department of Geosciences at USU. “The USU Department of Water, Earth, and Environmental Sciences (formerly Geosciences) is grateful to Mithril Mining Corp for providing site access and support as we train USU students to be the future of responsible critical minerals mining.”
Key Tungsten Highlights:
- A total of 65 fine-grained sediment and rock samples were collected at the Calvert Mine site. These samples were processed and analyzed at USU using pXRF and matrix-matched CRM standards to generate preliminary estimates of tungsten ore grade and rare earth element concentrations.
- Combining field- and lab-based pXRF analyses from skarn highwall exposures, skarn rock samples, and fine-grained material sampling locations with higher proportions of skarn rock types increases the average WO3 concentration to 0.152 wt. %.
- Several high-grade samples were recorded, including 1.45 wt. % WO3 in a skarn sample collected from the Section #11 ore pile.
- The investigation successfully identified the Upslope Zone 6 (UZ6) and the southeast portion of the Downslope Zone (DZ) as the most favorable locations for future mined ore removal and processing.
Rare Earth Element (REE) Potential:
- Field pXRF measurements indicated significant concentrations of high-value light rare earth elements (LREEs), including Ce, Nd, and Pr in skarn and skarn contacts in northwest cut highwalls.
- Promising LREE concentrations were also identified in skarn material in the DZ ore pile.
- These newly identified LREE concentrations highlight the potential for a secondary critical mineral revenue stream alongside tungsten extraction.
Future Deep-Seated Exploration Target:
In addition to surface material quantification, the report supports prior Calvert ore deposit models that suggest a deeper pluton as the source of tungsten-rich hydrothermal fluids. Locating a potential porphyry source for Calvert tungsten mineralization presents a highly compelling target for future geophysical surveys and exploration drilling.
Strategic Significance & Next Steps:
These results confirm the immediate operational value of surface materials at the Calvert Mine while establishing a clear roadmap for expanded subsurface exploration. By identifying Upslope Zone 6 and the southeast Downslope Zone as priority processing targets, Mithril Mining can efficiently focus near-term material removal, transport, and metallurgical testing on areas with verified higher-grade tungsten and rare earth element potential. Looking ahead, the Company plans to conduct whole-rock geochemical analyses (ICP-MS) and deploy magnetic and gravity geophysical surveys to map the deep-seated secondary intrusion responsible for the ore-forming fluids. Furthermore, Mithril will expand sampling across upper highwall outcrops and conduct comparative side-by-side testing between field and lab pXRF and traditional fire assay concentrations to establish a rapid, cost-effective assay protocol for future property evaluation.
About Mithril Mining Corp.
Mithril Mining Corp. is a U.S. and veteran-owned critical minerals exploration and development company focused on rebuilding America’s domestic tungsten supply chain and strengthening long-term resource independence.
Strategically located near existing infrastructure, processing corridors, and rail access, Mithril Mining is advancing verified American tungsten assets through disciplined exploration, responsible stewardship, and modern operational standards. The Company is committed to supporting U.S. manufacturing, defense readiness, and the creation of sustainable, high-value American jobs.
About Utah State University, Department of Geosciences
Utah State University (USU) is a premier public land-grant research university founded in 1888. Headquartered in Logan, Utah, it is classified as an R1 Doctoral University and enrolls over 29,000 students across statewide campuses and online. USU offers elite graduate and undergraduate research opportunities in disciplines including agriculture, natural resources, and aerospace.
The USU Department of Geosciences offers hands-on field instruction, computational modeling, and in-house laboratory research on Earth’s materials and systems within the S.J. & Jessie E. Quinney College of Agriculture & Natural Resources. The department is a recognized leader in water science, paleontology, earthquake geohazards, and energy and critical minerals research and provides degree options tailored to various career paths and specializations.
Contact
info@mithrilmining.com
