Rare earth elements are vital for technology and abundant in nature, yet they are hard to extract. Ukraine has significant reserves, while China controls 80% of the supply chain.

So-called rare earth elements refer to 17 chemically-similar, silvery-white elements that are used to make magnets – which in turn power motion for electric vehicles, cell phones, missile systems and other electronics. But how critical are they, and are they actually rare? Eric Onstad explains.