Root of "marten," "sable"

I've seen the Germanic *marthuz attested to, but can't the root be
taken further? Are there any other potential synonyms in other
Indo-European groups that could be traceable to a PIE root?
Relatedly, I've heard that the word "sable' comes from the Russian
"sobol," but where would that arise from?
As well, the word "ermine," I've heard, could arise from "mus
Armenius" or from a word akin to the Lithuanian "sarmuo~" and a
relative of the English "hoary," with a PIE root as "gray." Which is
most probable, the Armenian mouse or the Gray one? And if it's the
latter, does that denote a fear for it like that for the hare, or
might it be a reverence, since weasels would have eaten rodents and
lagomorphs such as hares?

I write stories with such creatures as protagonists, so with an
interest in languages and proto-languages (especially
Proto-Indo-European) this is a natural thing for me to study.