haha, but what _is_ it though, like as specific as the description is it feels like we should be able to figure it out

I think it's more to highlight its strangeness, unknowableness—to us as well as Severian: "metals…that were green & blue in the same sense that copper is said to be red or silver white, colored metals so curiously wrought [they might have been] works of art or…strange machines" Yet Severian knows>

good call on metaphor tho