Chinese scientists have made a groundbreaking discovery by identifying rare-earth biomineralization in the bracken fern (Pteridium aquilinum), paving the way for a greener and more sustainable approach to rare-earth element (REE) extraction. This marks the first-ever observation of natural biomineralization of REEs in vascular plants, challenging conventional geological understanding of mineral formation.

Key Findings

1. Biomineralization Mechanism
Researchers from the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (led by Prof. Zhu Jianxi) discovered that bracken ferns not only efficiently absorb and concentrate REEs from soil but also form monazite-(La) crystals—a phosphate mineral containing lanthanum—within plant tissues. This process occurs at ambient temperatures and pressures, unlike traditional REE mineralization, which requires high-temperature geological activities like magmatism or hydrothermal events .

2. Self-Defense Mechanism
The ferns act as "REE vacuums," absorbing dispersed REEs from contaminated soils. Through a self-protection mechanism, REEs are precipitated as nano-sized particles in leaf vascular bundles and epidermal tissues, eventually crystallizing into stable phosphate minerals. This immobilizes toxic REE ions, preventing cellular damage—a process analogous to how plants sequester heavy metals like arsenic or cadmium .

3. Environmental and Industrial Advantages
• Unlike natural monazite, which often contains radioactive uranium and thorium, the fern-derived biomineral is pure and radiation-free, eliminating safety risks in industrial processing.

• This discovery offers a dual-purpose solution: rehabilitating REE-polluted soils (e.g., tailings) while simultaneously recovering high-value REEs through biomass harvesting—a "remediation-coupled recovery" model .

Significance for Sustainable Resource Management

• Reduced Ecological Footprint: Traditional REE mining causes severe habitat destruction and pollution. Biomineralization-based extraction could minimize land degradation and water contamination.

• Supply Chain Resilience: With REEs critical for AI, renewables, and defense technologies, this method diversifies supply chains by leveraging plant-based resources, reducing reliance on geopolitically volatile mining regions.

• Scientific Innovation: The finding expands the understanding of plant-mineral interactions, inspiring research into other hyperaccumulators (e.g., Phytolacca americana) for mineral recovery .

By harnessing nature's intrinsic mineralization processes, Chinese scientists have unlocked a paradigm shift in REE sustainability. This breakthrough aligns with global efforts to balance technological advancement with environmental stewardship, offering a blueprint for circular economy solutions in resource extraction.

For further details, refer to the study published in Environmental Science & Technology (November 5, 2025).