Praseodymium, the green twin of the rare earth elements, represents one of the most fascinating chapters in the history of chemical discovery and technological innovation. This silvery-white metal, whose name derives from the Greek words “prasios” meaning green and “didymos” meaning twin, has journeyed from being an unrecognized component in mineral specimens to becoming an essential element in modern technology. From its initial misidentification as part of “didymium” in the 1840s to its current critical role in permanent magnets, fiber optics, and specialized ceramics, praseodymium exemplifies how scientific understanding evolves through persistent investigation and how seemingly obscure elements can become indispensable to technological progress. The story of praseodymium interweaves advances in analytical chemistry, the development of separation techniques, and the growing demands of emerging technologies, demonstrating how a single element can illuminate broader themes in the history of science and industry.

For more information, check out the light rare earth elements (LREEs) as a group, the heavy rare earth elements (HREEs) as a group, and all rare earth elements (REEs). Be sure to check out all other critical raw materials (CRMs), as well. The complete history of all 17 rare earth elements can be found here.

Read about the use of rare earths in quantum computing here.

A History Of Praseodymium

The history of praseodymium spans nearly two centuries, beginning with early confusion about rare earth elements in the 1840s and extending to its current status as a critical material for renewable energy and advanced technologies. Initially hidden within what was mistakenly identified as the element “didymium,” praseodymium remained unrecognized for over four decades until Carl Auer von Welsbach’s breakthrough separation in 1885. The subsequent development of pure metallic praseodymium in 1931 opened new possibilities, while the late 20th and early 21st centuries have seen its emergence as an essential component in permanent magnets, optical amplifiers, and specialized ceramics, reflecting its transformation from a chemical curiosity to a strategic material vital for modern technology.

Chronology

• 1803 – Ceria was discovered by Jöns Jacob Berzelius and Wilhelm Hisinger in Sweden, and independently by Martin Heinrich Klaproth in Germany, setting the stage for future rare earth discoveries including praseodymium [1]
• 1874 – Per Teodor Cleve discovered that didymium actually consisted of two elements, later identified as neodymium and praseodymium [4]
• June 1885 – Carl Auer von Welsbach successfully separated didymium into praseodymium and neodymium in Vienna through fractional crystallization of ammonium didymium nitrate, performing over one hundred fractional crystallization operations (each lasting up to 48 hours) to separate praseodymium salts (greenish-brown) from neodymium salts (pink), naming praseodymium using the Greek words “prasios didymos” meaning “green twin,” reflecting its green salts and close association with neodymium [1, 2, 3, 5, 6, 7]
• November 1927 – Leo Moser at Moser Glassworks in Karlovy Vary (Czech Republic) conducted the first experimental glass melts involving praseodymium and other rare earths [8, 1]
• Spring 1929 – Leo Moser investigated the use of praseodymium in glass coloration, yielding a yellow-green glass named “Prasemit,” and in 1928 developed additional rare earth glasses including Heliolit (combining praseodymium and neodymium in 1:1 ratio), showing color-changing properties; the Alexandrit and Heliolit names were registered as trademarks by Moser [1, 8, 9, 10]
• 1903 – Carl Auer von Welsbach patented ferrocerium, a pyrophoric alloy containing cerium (70%) and iron (30%), with later versions including praseodymium and other rare earth elements for cigarette lighter flints [2]
• 1907 – Treibacher Chemische Werke GesmbH was formed by Welsbach to build and market ferrocerium devices containing praseodymium [2]
• 1910 – Ronson released the first Pist-O-Liter, using ferrocerium flints containing praseodymium [22]
• 1931 – Pure metallic praseodymium was first produced, 46 years after its discovery [2, 3, 11, 12]
• 1932 – Zippo lighter company was founded by George Grant Blaisdell, using ferrocerium flints containing praseodymium in its products [22]
• 1986 – Magnequench was founded by GM to commercialize NdFeB magnets containing praseodymium [15]
• 1987 – Gain and lasing in erbium-doped fibers were first demonstrated by two groups (one including David N. Payne, R. Mears, I.M Jauncey and L. Reekie from the University of Southampton and one from AT&T Bell Laboratories, consisting of E. Desurvire, P. Becker, and J. Simpson), paving the way for praseodymium-doped fiber amplifier development; in the same year, Willems and Buschow demonstrated a successful NiMH battery using rare earth alloys including lanthanum and neodymium compounds, establishing the foundation for praseodymium use [13, 16]
• 1989 – First consumer-grade NiMH cells containing praseodymium became commercially available [13]
• 1990 – NiMH rechargeable batteries containing praseodymium were commercialized [14]
• 1990s – First large-scale wind farms using permanent magnet generators began incorporating praseodymium in NdFeB magnets [23]
• 1997 – Toyota Prius, the world’s first mass-produced hybrid electric vehicle, adopted cylindrical NiMH batteries containing praseodymium [17]
• Early 2000s – Praseodymium-doped fiber amplifiers for 1.3 μm optical communications became commercially available [16]
• 2002 – Development of cubic Ca-ZrO₂ ceramic stains using praseodymium as dopant for yellow pigments was published [18]
• 2005 – Sanyo introduced Eneloop low self-discharge NiMH batteries with improved electrode components including praseodymium [13]
• 2014 – Praseodymium became increasingly important in NdFeB permanent magnets, with addition improving corrosion resistance and coercivity, typically replacing some neodymium content in the magnets [19, 20]
• 2015 – Nitto Denko announced new sintering method for neodymium-praseodymium magnets [15]
• 2018 – Stockholm University researchers developed protective layer for metal hydride surfaces in NiMH batteries to extend cycle life [21]
• 2022 – U.S. Department of Commerce investigation highlighted praseodymium as critical for NdFeB permanent magnets, noting 30% rare earth content by weight [22]
• 2023 – Federal Register published report on NdFeB permanent magnets emphasizing praseodymium’s role in national security and renewable energy [22]

Final Thoughts

The trajectory of praseodymium from an unknown component in misidentified minerals to a critical element for sustainable technology illustrates the unpredictable nature of scientific discovery and technological application. What began as a chemical puzzle in the 19th century has evolved into a strategic material essential for electric vehicles, wind turbines, and optical communications. The element’s history demonstrates how fundamental research, driven initially by pure scientific curiosity, can yield discoveries of profound practical importance decades or even centuries later.

As the world transitions toward renewable energy and seeks to reduce carbon emissions, praseodymium’s role in permanent magnets and energy storage becomes increasingly vital. The ongoing challenges of sustainable extraction, recycling, and reducing dependence on limited geographic sources of praseodymium mirror broader questions about resource security and environmental responsibility in the 21st century. The history of praseodymium thus serves not only as a chronicle of scientific achievement but as a reminder of the complex interplay between discovery, innovation, and the evolving needs of human society.

Thanks for reading!

References

[1] Praseodymium – Wikipedia – https://en.wikipedia.org/wiki/Praseodymium

[2] Praseodymium – https://www.chemicool.com/elements/praseodymium.html

[3] Praseodymium | History, Uses, Facts, Physical & Chemical Characteristics – https://periodic-table.com/praseodymium/

[4] Praseodymium – Rare Earths – https://rareearths.com/praseodymium/

[5] Praseodymium Facts, Symbol, Discovery, Properties, Uses – https://www.chemistrylearner.com/praseodymium.html

[6] It’s Elemental – The Element Praseodymium – https://education.jlab.org/itselemental/ele059.html

[7] Praseodymium | Rare Earth Element, Atomic Number 59 | Britannica – https://www.britannica.com/science/praseodymium

[8] Didymium – Wikipedia – https://en.m.wikipedia.org/wiki/Didymium

[9] Praseodymium: a metal that generates cold | MEL Chemistry – https://melscience.com/US-en/articles/praseodymium-metal-generates-cold/

[10] Moser (glass company) – Wikipedia – https://en.wikipedia.org/wiki/Moser_(glass_company)

[11] Praseodymium – MMTA – https://mmta.co.uk/metals/pr/

[12] Praseodymium – Element information, properties and uses | Periodic Table – https://periodic-table.rsc.org/element/59/praseodymium

[13] Nickel–metal hydride battery – Wikipedia – https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery

[14] Nickel Metal Hydride Battery – an overview | ScienceDirect Topics – https://www.sciencedirect.com/topics/materials-science/nickel-metal-hydride-battery

[15] Neodymium magnet – Wikipedia – https://en.wikipedia.org/wiki/Neodymium_magnet

[16] Praseodymium-Doped Fiber Amplifier (PDFA) – FiberLabs Inc. – https://www.fiberlabs.com/glossary/praseodymium-doped-fiber-amplifier/

[17] Development of nickel/metal-hydride batteries for EVs and HEVs – ScienceDirect – https://www.sciencedirect.com/science/article/abs/pii/S0378775301008898

[18] Praseodymium-doped cubic Ca–ZrO2 ceramic stain – ScienceDirect – https://www.sciencedirect.com/science/article/abs/pii/S0955221901005179

[19] All About Neodymium Iron Boron (NdFeB) Magnets (Properties, Strength and Uses) | Be-cu.com – https://be-cu.com/blog/ndfeb-magnets/

[20] How Neodymium NdFeB Magnets are made – https://e-magnetsuk.com/introduction-to-neodymium-magnets/how-neodymium-magnets-are-made/

[21] Is Nickel Metal Hydride (NiMH) Still Viable? – https://www.batterytechonline.com/materials/is-nickel-metal-hydride-still-viable-

[22] Lighter – Wikipedia – https://en.wikipedia.org/wiki/Lighter

[23] New Partnership to Extract Rare Earth Magnets from Retired Wind Turbines for Use in New Ones | Offshore Wind – https://www.offshorewind.biz/2023/09/12/new-partnership-to-extract-rare-earth-magnets-from-retired-wind-turbines-for-use-in-new-ones/