@stewrubenstein You are the sole hit I got when searching #chemistry. So congrats.. you get to hear my question :)

I bought some white lime. This stuff starts oxidization after the bag is opened. I think I had it unsealed for like ½ a year. It’s now just a month or two past expiry. I’d like to know if it’s turned to chalk or if it’s still lime. I mixed a sample with water & let it dry overnight. When I crush it between my fingers, it crumbles back into a powder. Does that mean I now just have a useless bag of chalk? It’s hard to tell because mortar from lime is soft anyway. So crushing a chunk of it might not be the best test.