From smartphones to satellites, Rare Earth Elements (REEs) power our world, yet their unfamiliar names and symbols can make them seem mysterious. Despite the term “rare,” a 2010 report estimated that REEs are more abundant in the Earth’s crust than commonly mined metals like copper and zinc. They are not “rare” because they cannot be found, but because they rarely occur in high enough concentrations to be mined economically. Geological processes start the refining process, and we finish the job.

At the atomic level, REEs are larger and heavier than similar elements, which prevents them from fitting into the crystal structures of common minerals as magma cools, so REEs are among the last elements to be incorporated into minerals. Think of magma as a crowded party – the common guests (elements like silicon, oxygen, and aluminum) group up early, and REEs wait to dance until they can find elements like sodium, calcium and potassium. This process is nature’s way of concentrating REEs — a process that continues even after the rocks reach the surface.

Once at the surface, they may occur in mineable concentrations. If not, erosion breaks down these rocks over time, and rain and wind transport the mineral fragments. Their larger atomic sizes influence where these sediments settle – often in clays or placer deposits with concentrations of REEs high enough to be considered valuable. Even so, extracting usable REES from these deposits remains a complex, costly, and sometimes environmentally challenging process.  The real rarity lies in the mining, processing, and distribution – not the elements themselves.

REEs make up only about 4% of your cellphone – roughly 1/8^th of an ounce – but without them, your phone would go dark. BUZZ! You got a like! That’s neodymium vibrating. Snapping a selfie? Lanthanum is behind that pic. Even the colors on your screen owe their brilliance to europium and terbium. Our tech-driven world depends on REE-bearing minerals.

Discover the mineral magic driving your devices in our Special Exhibit: “The Hidden Gems of Cellphones”, which reveals the minerals behind the screen and the elements that power your digital life. The Exhibit opens Sunday October 19^th. Join us for tour and mingle at 2 p.m. Light refreshments will be available.

REFERENCES

Gómez, Moisés, et al. 2023, Critical and strategic metals in mobile phones: A detailed characterisation of multigenerational waste mobile phones and the economic drivers for recovery of metal value: Journal of Cleaner Production, vol. 419, p. 138099, Available at https://doi.org/10.1016/j.jclepro.2023.138099. 

Long, K.R., Van Gosen, B.S., Foley, N.K., and Cordier, Daniel, 2010, The principal rare earth elements deposits of the United States—A summary of domestic deposits and a global perspective: U.S. Geological Survey Scientific Investigations Report 2010–5220, 96 p. Available at http://pubs.usgs.gov/sir/2010/5220/.

Van Gosen, B.S., et al. 2014, The Rare-Earth Elements—Vital to Modern Technologies and Lifestyles: USGS Mineral Resource Program, Fact Sheet 2014 –307, http://dx.doi.org/10.3133/fs20143078.