Critical Minerals: Renewed Exploration with Hyperspectral Remote Sensing

Why Critical Minerals Matter

The renewed urgency around critical mineral exploration stems from the need to secure stable, sustainable, and sovereign supply chains, particularly for defense, clean energy, and infrastructure. Since the mid-1990s, China has dominated REE production (Figure 1), while most of the world’s lithium, cobalt, and graphite originates from Australia, Democratic Republic of Congo, and China, respectively. China also processes the majority of global lithium and cobalt (Figure 2).

The 2020 U.S. Energy Act formally defined “critical minerals” as non-fuel resources essential for economic and national security, and subject to potential supply chain disruptions. Criticality is dynamic and reflects evolving risks related to resource availability, geopolitical policy, environmental concerns, and market economics. These minerals face vulnerabilities across extraction, processing, manufacturing, and end-use stages, factors which the U.S. Geological Survey (USGS) evaluates in maintaining its official list of 50 critical minerals and elements (USGS 2022). This list features resources such as nickel and zinc but notably excludes uranium as it is considered a fuel source. However, the Department of Energy considers it “near critical” due to potential short- and medium-term supply risks.

Figure 1: Global Production Comparison of Rare Earth Elements from 2010 to 2012 (Kim et al 2025 and references therein).

Figure 2: Global Production Comparison of Critical Minerals for Battery Manufacturing in 2019 (Rowan 2025 and references therein).

The Role of Technology in Critical Mineral Discovery

Advanced technologies are transforming how we identify and assess mineral resources. Geophysical imaging methods, such seismic and magnetic surveys, reveal subsurface structures and properties that guide exploration. Meanwhile, remote sensing platforms (satellite and airborne) detect surface structure features like faults, folds, and fracture zones which often indicate the presence of buried mineral deposits.

With high-quality hyperspectral imaging data becoming increasingly available, hyperspectral remote sensing is emerging as the first choice in critical mineral exploration. By analyzing how light interacts with Earth’s surface across hundreds of narrow spectral bands, hyperspectral systems can detect hydrothermal alteration zones and key indicator minerals such as carbonates, clays, and iron oxides. These alterations, caused by circulating hot fluids within the Earth’s crust, modify minerals. While not typically categorized as critical, their presence may reveal geochemical pathways that mobilize and concentrate REEs, niobium, and gallium.

In addition, REE deposits can form through fractional crystallization, where specific elements are enriched in the final stages of cooling magma. Hyperspectral data can reveal signatures associated with these mineralized zones, giving geologists with assisted hyperspectral data processing a critical edge in identifying viable deposits.

Spectral Science Behind Hyperspectral Imaging

Each mineral has unique reflectance spectral signatures due to their interactions with light across the electromagnetic spectrum.

• Electronic interactions (visible to near-infrared wavelengths) – caused by electron transitions between different energy levels within atoms or molecules.

• Vibrational interactions (near-infrared to shortwave-infrared) – due to the stretching and bending of molecular bonds.

Hyperspectral imaging exploits these interactions to detect diagnostic absorption features and differentiate minerals with high specificity.

 

Exploration Highlights in the Southwestern U.S.

Several well-documented hyperspectral mapping efforts demonstrate the effectiveness of this technique:

• Cuprite, Nevada – Hydrothermal alteration mapping (Swayze et al. 2014)

• Karnes County, Texas – Uranium mine sites and host rock analysis (Hubbard et al. 2023, 2024)

• Battle Mountain, Nevada – Magmatic-hydrothermal zones (Meyer et al. 2024)

• Mountain Pass, California – REE-rich carbonatite mapping (Asadzadeh et al. 2024)

 

Mountain Pass: A Case Study in Hyperspectral REE Detection

Located In California, the Mountain Pass mine is the only active REE mine in the United States. It was the world-leading producer of light REEs until China took the lead in the early 1990s (Hammarstrom & Dicken 2019). Since 2017, production at Mountain Pass has climbed to ~42,400 metric tons of total rare earth oxides (MP Minerals).

The primary ore is bastnaesite, a fluorocarbonate mineral rich in cerium (~50% by weight), followed by lanthanum, neodymium, and praseodymium (Kim et al. 2025). Its high REE content makes it a prime target for hyperspectral detection.

To characterize this deposit, scientists have applied advanced spectral detection techniques to airborne and satellite data from EnMAP, EMIT, PRISMA, EO-1 Hyperion, and AVIRIS (e.g., Gadea et al. 2024). Data was analyzed at resolutions ranging from 3 to 30 meters.

New Indices and Breakthroughs

Researchers recently developed new spectral indices to detect bastnaesite using laboratory reflectance spectra (Gadea et al., 2024). These indices quantify REE concentrations with high accuracy. With current technology, deposits containing >3.3% REEs by weight can be confidently detected in hyperspectral imagery (Figure 3).

Figure 3: Example detection map of REEs (right panel) within Mountain Pass Mine area using new REE-rich bastnaesite spectral indices (left panel inset) from laboratory reference spectra (Gadea et al. 2024). Visible hyperspectral image (left panel) of mine area is provided for reference.

Figure 4: Baseline-removed spectral fitting result of EnMAP Mountain Pass mine spectra (black line; left panel) using laboratory-based spectral signature of REE-rich bastnaesite (red line; left panel) to confirm detection of REE neodymium (Nd) electronic features at ~580, ~740, ~800, and ~865 nm (Asadzadeh et al. 2024). Additional vibrational features near ~2340 nm (right panel) also indicate the presence of calcium carbonate within bastnaesite.

In addition to index-based detection, spectral fitting methods have been used to match measured reflectance signatures. These were applied to EnMAP data to identify neodymium absorption features at ~740 and ~800 nm (Figure 4). This technique enabled detection of neodymium not only within the open mine pit but also across tailings storage sites, the crusher site, waste storage area, and evaporation ponds (Figure 5).

Conclusion: The Future of Remote Sensing for Critical Minerals

Hyperspectral imaging is revolutionizing how we explore critical minerals. As seen in Mountain Pass and other sites, these techniques can:

• Detect REE-rich alteration minerals with high spatial and spectral precision

• Map mineral abundance across active mines and unexplored terrain

• Identify new targets for sustainable domestic mineral production

In a world where mineral supply security is intertwined with energy independence and national resilience, remote sensing is not just innovative; it’s essential. NV5’s advanced software and services empower organizations to unlock the full potential of hyperspectral imagery for critical mineral exploration. With industry-leading tools like ENVI® image analysis software, and deep domain expertise in spectral analysis, NV5 helps geologists, mining companies, and government agencies efficiently identify and map valuable mineral resources. Whether through custom analytics, remote sensing workflows, data acquisition, or data fusion services, NV5 supports end-to-end solutions that accelerate discovery, improve decision making, and drive sustainable resource development.

Figure 5: EnMAP hyperspectral map revealing the distribution and relative abundance of the REE neodymium (Nd) within the Mountain Pass mining site (Asadzadeh et al. 2024).

GeoAgent: From Prompt to Product

NV5 is also pioneering the use of AI and is developing GeoAgent, which is designed to interpret natural language, invoke geospatial tools, and execute end-to-end workflows. During recent development testing, GeoAgent was asked to search an area of interest for neodymium, a rare earth element essential to wind turbines and electric vehicles. GeoAgent quickly grabbed hyperspectral data over the area, built and executed a workflow, and returned a mapping solution that highlighted areas on the ground likely assoicated with neodymium. This upcoming capability demonstrates how advanced NV5 technology can dramatically accelerate mineral discovery workflows, from targeting to prioritization. 

Earth MRI: Supporting the National Mapping Mission

Since 2019, NV5 has been a key partner in the Earth Mapping Resource Initiative (Earth MRI), led by the USGS. Under this program, NV5 provides advanced geophysical services, primarily magnetic and radiometric surveys, to identify critical mineral resources across the United States, including Alaska and U.S. territories. Our contributions include:

·      Retrofitting aircraft for high-resolution survey missions

·      Acquiring and processing geophysical data to improve subsurface modeling

·      Enhancing national geologic maps and supporting mineral security goals

This initiative underscores NV5’s role as a trusted partner in national-scale exploration and resource planning.

If you’re exploring opportunities in critical mineral discovery and want to learn how NV5 can help, whether through hyperspectral analysis, geophysical survey, or advanced automation, contact our team at GeospatialInfo@NV5.com. Let’s explore what’s possible together.