Re: Rainbow Gem - Where do you find it?
Apparently collecting is a hidden skill so your sim first has to skill up before these will spawn. That's not entirely true. Someone in your town has had to have skilled up before these will spawn. Once they start spawning then they will occasionally re-spawn and can be found by anyone. You can find mods to monitor your hidden skills. There is also a gem spawner mod.
Don't really like mods to much, cos they sometimes are more trouble than they worth if they get corrupted, I will just keep my sim searching and searching and searching, at least he getting very very rich from all the gems and metals he has found, (plutonium got him out of debt)