My lithops split for the first time this season and I completely panicked over nothing
So I have been growing these things for about two years now, and I genuinely thought something had gone wrong when I noticed the skin on my oldest one starting to crack open down the middle last month. The plant looked almost deflated, slightly wrinkled around the edges, and the gap between the two leaves was widening in a way that seemed alarming. I pulled it out of the pot to check the roots (which, for the record, you should not do mid-molt, I know that now).
Turns out everything was completely fine. The new pair of leaves was already forming inside, pushing through right on schedule. The outer leaves dried up over the following few weeks and the new body emerged looking almost artificially perfect, smooth and patterned like a little river stone. The whole process took maybe five or six weeks start to finish.
A few things I noticed that might help anyone else who is watching their first split:
The old leaves will look bad before they look better. Mine went papery and translucent and I was convinced they were rotting. They were not rotting. Just drying out as they should.
Withholding water during this period actually matters. I gave mine absolutely nothing from the time I saw the first crack until the new leaves were fully out and the old ones had dried almost completely. Every guide says this and every guide is correct.
Light seemed more important than I expected. The plant sits on a south-facing sill and I think consistent bright light kept the process moving without stalling.
The one thing I am still uncertain about is timing the first post-molt watering correctly. I waited until the outer leaves looked like thin papery husks and then gave a small, careful drink. The plant seems happy but I would be curious what others do here. Do you water once the old leaves are fully dried, or do you wait even longer than that?