Julius: you're doing damage, especially with the critical hit. It's got hardness 8, so it's soaking quite a bit; in theory I should be more strict, as the sword shouldn't really work, but hardness 8 does the job for our purposes.
There is a digging kit in the wagon, including a pickaxe and a shovel. If anyone bought a climbers kit, that would have a suitable hammer. Yes, a hammer will do more damage; and if you have a spike to drive into the gem, you'll automatically get it.
Rangerjohn: it's every round you're in there, I suppose. One should do for now. If you don't leave the swarm I'll get you to Fort save each round, then when you leave or save we'll start counting the rounds. I think that makes sense.