Sorry, that one's a goner. Without the taproot, it's just a pair of dying leaves. If you like Lithops, it's very rewarding to grow them from seed.

I tried growing lithops once, and it was the last time. In my experience, I found just overwatering once to be fatal, turning the living rock to dead mush within hours. If a cactus starts to rot from overwatering, often part of the plant can be saved before the rot spreads, but not so with lithops. They are fascinating plants, good for a specialist, but for anyone with a propensity toward heavy handed watering, there are many other more forgiving succulents to choose from. Christopher

Mesembryanthums (Lithops, pleiospilos, baby's toes etc) would not grow all that well in Brisbanes hot humid climate. Need to be trying plants that are happy with this type of conditions. There is a very active group of Cactus and Succulent growers in the Brisbane area. Their details would be on the web. Joining this group you would have access to all the relevant info and plants too. Good Luck.

If it's only been a few days its possible the damage was done (and it's already too late...) before you brought it home, sadly. Have you watered it since acquiring? My home depot lithops experience is that I watered mine once, and that was enough to do it in. Timing is everything with lithops... not sure if mine had been already been abused, or one poorly timed watering is enough to do them in. About the actual damage, it -could- be oedema, I don't recall seeing anything like that on mine, but maybe I didn't notice it. Daniel