My fiancee and I were discussing the worst metal to use to make armor, and the obvious answers are lead and gold, but she cunningly suggested mercury. Which is a fair point, but then I wondered if solid mercury is any good. Googling told me that the melting point of mercury is -38° c (-37° f), so first you get it really fucking cold. At that point, it turns out that mercury has a tensile strength of 1900 mpa, compared to lead’s 18 and steel’s ~500-940 (depending upon the kind of steel).
Now, I know that tensile strength is not necessarily the best measure of a material’s ability to function as armor, but I’m a liberal arts major and didn’t care to actually do that much more research before going straight to, “EVIL ICE DEMONS IN MERCURY ARMOR. THE PCS CAN’T LOOT IT BECAUSE WHEN THEY PUT IT ON IT MELTS AND KILLS THEM.”