Tried vinegar on a weird rock from the creek and it fizzed like crazy

I was cleaning some finds from the creek near my house and had this one lumpy, gray rock that felt kind of chalky. On a total guess, I dropped some plain white vinegar on it, and the thing started fizzing and bubbling like a science fair volcano, lol. I had no idea it would react that strong. Turns out it's a big chunk of limestone, which I guess is pretty common, but I'd never actually seen the acid test work in real life before. It was way more dramatic than the little bubbles they show in books. Now I keep a tiny bottle of vinegar in my field kit just for quick checks. Has anyone else had a rock react way more than you expected?

3 comments

3 Comments

ray_webb62mo ago

What creek did you find that in?

fisher.diana2mo ago

Check if it fizzes with lemon juice too, it's a stronger acid.

xena_anderson1mo ago

Keep a tiny spray bottle of diluted muriatic acid for the really stubborn stuff, limestone can get a coating that vinegar won't cut through. I've had creek rocks bubble for a full minute with the stronger stuff when vinegar barely touched them. Just be careful with that acid and wear gloves, it's no joke on your hands.