Why does my sodium acetate look like metalic magma?
I wouldn't bother trying to purify it. As Mithoron said in his legendary comment "Caramel made your product a black unholy abomination of science". I would have distilled the vinegar and diluted it (because concentrated acetic acid is a bit dangerous if you don't know what you're doing) and start again. If you want pure product, make sure your starting materials aren't filled with "unholy abomination of science" causing impurities. If you really want to purify it, maybe recrystallise it in hot water? Or a solvent that sodium acetate can become saturated in.