Prismatic Ponytails
I was thinking about what would have happened if my father had come to exploit it, only for someone else to buy the mine instead and hand it over directly to the people. Whatever they worked, then, they would be working for themselves. The diamonds sold would be sold by them, and my father would have been forced to negotiate.
... But I suppose no matter what, there's some corruption to face. If we say the town owns it and the Mayor is in charge then something exactly like what you're describing is heavily likely. Sigh.