Another interesting thing to add to the Overview, would be Red Marble Mine on the east side. Although marble was present, it appears that the main target was red magnesite that is used primarily to line steel furnaces.
"So I was sitting in my cubicle today, and I realized, ever since I started working, every single day of my life has been worse than the day before it. So that means that every single day that you see me, that's on the worst day of my life."
--Peter Gibbons (Office Space)