You are confusing Bonedigger with Stonegrinder. Stonedigger drops the Stone Thunder, which is 10 34 magic lore. Bonedigger didnt drop anything the 3 times I have killed him so far.
This guy is well below level 35. I was 38 and he conned green to me. All he dropped was a jade magma which is apparently for the monk shackle of bronze quest.
I'm guessing 35 might be the high end of a range (whoops, hit post by mistake). I killed him easily at 39 and he was green. Didn't drop anything a normal miner wouldn't (jade magma, for instance), but then I only killed him once.