SAMARIUM

A return to normality compared to its beta-decaying, radioactive next door neighbour, promethium, samarium very much is an element with stable isotopes, and like many other rare earths was discovered during the 19th century. Samarium is an element named for a mineral named for a man; the man was a Russian mining general whose last name was Samarsky, whose colleagues must have thought of highly as they named a mineral in his honour - samarskite. And when a new element was found in samarskite, the name of the element became samarium. Samarium does oxidise a bit in air, but is surprisingly stable in air, and retains shine in mineral oil, much more so than does its neighbouring europium which happens to be the lanthanide most willing to submit to atmospheric oxygen and corrode rapidly. But still, for the most part it looks as most of the lanthanides in my collection do – a dark, metallic, mostly nondescript lump of metal at the bottom of an oily vial where its shape is distorted unless it’s on the near end. As is the case with - coincidence - Europium, quite a bit of the isotopes of Samarium are ever so slightly radioactive, usually decaying over many zeroes of years, almost always into a stable isotope of neodymium. Nearly 40% of samarium in nature is ever-so-slightly radioactive. Magnets which incorporate samarium resist demagnetisation well. I assume that's a good thing. This sample of samarium was obtained in July of 2025.