I can't "mine" any of the gems on the walls.
Hint 1 of 6:
Your "thought process" tells you that "there must be a better way".
Hint 2 of 6:
Surely you don't just expect to pick ore out of clusters on the walls!
Hint 3 of 6:
You'll need some kind of tool to mine the various gems you find.
Hint 4 of 6:
General Outfitters offered a Rock Filet for this purpose, but they were sold
out.
Hint 5 of 6:
You'll need to obtain a Rock Filet somehow.
Hint 6 of 6:
You won't find one -- intact, that is -- anywhere in the game.