Finally finished my quarry mine about a week or so ago.
I found about two or three full stacks of coal, 40 redstone, 20 lapis, maybe 16 gold ore, I don't remember how much iron because I used most of it to make new pickaxes, and enough cobblestone to fund my building projects for the next 20 years. (Uh, more or less.) And I exhausted probably more than 30 iron pickaxes to mine it all.
My goal was to find diamonds.
So here comes my favorite part...
12 diamonds in all, baby!
Except I don't know what I want to do with them :S