It has flowered last summer (in white) and I remember that I tried to pollinate some of the flowers. Nothing really happened and I thought that the flowers had just dried out and were now still on the plants.
Then I scraped off some of the dry flower parts and suddenly I saw something I didn't quite believe.
This is actually a seed capsule. It was the structure that convinced me. The five parts that look like pieces of a cake and the round shape of it...
However the whole "thing" was very dry and didn't really look like seed capsules I had seen in pictures up until now. Those had always been greenish, big, tight and sat closely on top of the leaves. This one hangs loosely on a dried stem...
But I thought there is only one way to find out if it's really a seed capsule: make it wet!
So I did and I must say I am glad that I had my camera right beside me, because suddenly the seed capsule started to open.
By the way: it seems to be important to not only put a drop of water ON the seed capsule but to also let a drop of water run down the stem. That seems to trigger the opening mechanism. On two other Lithops I found seed capsules just like this one (ones I would never have thought to be there) and one only got wet on top and it didn't open.
At this point the capsule stopped opening so I put in another drop of water. Unfortunately I also got the seeds wet in the process.
I took the seeds out with the tip of a paper clip. There was no other way to get them out of there, because the seed capsule is actually incredibly small and the seeds are even smaller. They only look quite big on the pics. I didn't even see that there were still seeds left in the capsule until I looked at this picture. With the naked eye there was nothing to be seen.