LITHOPS ASCENDING DISCOLORATION

[Antonio]

Hi! I’m a new member writing from Spain (sorry if my English is not the best!).

I’ve just bought my first lithops about four weeks ago and I am seeking some advice/knowledge on the plant from the pictures.

I got all of them bare root and I potted them in quite a mineral mix (around 80% aquarium gravel + pumice and 20% regular commercial potting soil). I gave them their first spraying a few days ago after they had been in the pots for three weeks.
They receive good natural light but no direct sun and look healthy to me. Some, that came a bit wrinkled, have even recovered the turgidity before watering. Others are wrinkling now and I will see how they respond to the spraying/watering.

The one that bothers more is this one on the pictures. The day I sprayed the other ones I noticed this discoloration on the body that seems to be ascending through it. Having a look at the pictures I took the day I received them, I believe (not sure) that the problem was already showing, but it was not that evident. I just didn’t notice.

I don’t know if it is a rooting problem or some infectious or parasitic disease, or maybe it has just not adapted. The plant is turgid, not soft at all, and is the only one that has not been watered yet, just in case. From above, the windows look very healthy.

I would much appreciate it if someone with more expertise could shed some light! I am scared the problem could spread among the others.

Many Thanks!!