The Grimstone Ledge

An obsidian seam at the Grimstone ledge keeps breaking under the pick. The foreman wants help.

Requirements

Find the foreman at Grimstone Bank
The foreman has a bandaged hand and a half-broken pick on the counter. 'Three of my best are off the seam this week. It's cracking wrong. Come up to the ledge.'
Inspect the cracked seam
The face shears in shells, not blocks. Wherever you set the pick, the stone splits the wrong way. The seam's been worked by someone who didn't know obsidian.
Borrow the arc's tempering field
The arc keeper lets you stand a chisel head under the field for an hour. It comes out humming and warm. The arc keeper marks the chisel and waves you off.
Reset the chisel at Ironice
The Ironice smith reseats the chisel into a fresh haft and tempers it twice. 'This is what your seam wants. Strike the cleavage line, not the face.'
Work the seam with the new chisel
The first strike rings. The face splits clean along the cleavage and a slab the size of a wagon wheel drops free in one piece.
Haul the run to Snowthorn for stockpile
The Snowthorn stockpile foreman counts the slabs and writes a number on a slate that makes him whistle. 'The Grimstone face hasn't done this in five years.'
Walk the seam end to end
You walk the cleared face. The seam runs another forty yards into the cliff. The foreman will have his crew back on it before the week ends.
Settle up with the foreman
He counts gold onto the counter without looking up. 'You taught my crew the cleavage trick. That's worth more than the slabs. Don't be a stranger.'