Our final stop on the rare earth periodic table is to number 64, gadolinium. And you might be thinking, egad! Why should I care about this element that I can barely pronounce!? Well, actually, you should.
Like all the other rare earth metals, it is a silvery metal that is soft and reacts slightly with oxygen and water (so it oxidizes in air to produce a black layer on top).
Gadolinium was discovered in the time period of 1880-1886, right around when chemists got good at separating rare earth metals from their native alloys. Remember, they are rarely found as an individual ore.
Gadolinium is special among the rare earths and in the periodic table overall, taking the title of “most paramagnetic” (aka highly polarizable, much in the same way a magnet works). As such, it is used as a contrast agent for MRI scans. And so enters the controversy. While Gd is used widely for MRIs, it has also recent been linked to onset diseases such as nephrogenic systemic fibrosis (NSF)— occurring mostly in patients with compromised kidney function. However, the link is not well understood and the data is not strong.
While this is cause for further investigation, there is no doubt that gadolinium plays a critical role in modern technology. Whether in screens, or improving iron alloys of in nuclear reactor cores, this metal is one we should celebrate!
Thank you for following along on our Rare Earth Summer adventure!
