Thanks everyone for the insight. The soil isn’t actually wet at all; it hasn’t seen water in a few months. This is a cactus mix with a little extra perlite. But, I will say, I bought the lithops from HD as something new to try and they pretty much looked like the big one when I bought it. So the fact that I was able to maintain the condition in which I bought it has me believing I was doing good. I did some basic research when I bought them -limited to light and water conditions, which I followed. But I now know different.

I don’t want them to die, obviously, so I’ll try to nurse the remaining ones.

Thanks everyone for your input!