This is making me think of one of the TOS novels - Spock's Planet, I think - where there's a family of precious gem 'miners' who find them in space. Anyone else remember it?
"Spock's World" - yes, the family that finds the asteroid that is going to make them rich and the head of the family doesn't want to get out of the business and retire on the proceeds... There was some...disagreement...on that point.
^Yes, I remember it doesn't end well. I couldn't check the part of my bookcase where the Trek novels are, because the Christmas decorations are still in front of it, waiting to be put back in the attic. It was driving me nuts trying to remember the exact title, so thanks!