We don't have experience painting fireplaces, but would instead recommend covering the stone with a stone veneer for an easy update. You could then choose the color and style of the stone to better match your decor, and add a mantle to match.

Thank you North Star stone for your idea! I had spoken with the stone company that did my fireplace surround on my new gas fireplace, but they didn't want to get involved as the stones on this old fireplace are varying depths and give a bumpy surface. Wish you were located in NJ... Should I shop other stone companies, or are your facades made specifically for uneven surfaces?

Have you already solved the chimney problems that led to the soot stains?

Have you tried toothpaste to remove soot?

There is a cleaner call Krud Kutter that a contractor friend told me about. Pick it up at Home Depot. He uses it to remove soot just like your needing.

I agree with Ikilgore75 and clayw's suggestions, and if you are not happy with the results you can stucco over the stone, european style.

I do not care for painted stone. I would even look into having it
Professionally cleaned if they are able to get it off this stone would be beautiful.

Try everything to clean it first and add a natural wood mantel depending on the style of your furnishings. You could go with unfinished, satin or gloss finish.

I would paint it so it would look nicer.

Hello! Came across this post and wondering if you ended up painting the stone and how it turned out? Contemplating painting mine too...