Re: gemstone grotto??
Meh... still looking for it - I had guessed where it was, coulnd't fine it, came here, got the directions, still can't find it.
EPIC FAILURE
Going to have another walk in the woods (rookridge) and find it. Hopefully I shall be a bit more luckier this time.
EDIT:
Found it ^^ I knew from the start what the place looked like, I just wasn't able to get to it.
Fast travel to Hobbe's Cave in Rookridge. Then turn back straight away and leave the cave. Go into the water and swim to the right onto that sandy beach with the crates. Now just keep going in that direction and voila