I have better lore for life essence. The smeltery actually infuses the metal with life, and so it discombobulates into a mass of individual organisms, a tiny ecosystem inside the smeltery. Some materials resist each other, while some are naturally attracted to each other (alloying mechanic) and by pouring the metal into a mold, you give them a much smaller environment to move in, and as such they quickly die out and leave a mundane tool part.
But I think sir jdog here was asking for something that they could use in a personal pack not something to add to a public magic themed pack. In which case, there's not really any alternatives I can think of.