Diamonds Are a Girl's Best Friend?

By now, you must think I'm a zealot... but you see my point? Suppose you are thinking of marrying your sweetheart and want to purchase a diamond ring. Hopefully you do your research, go to a reputable jeweler, learn about the 4Cs... and after all is said and done, make an informed purchase... beautiful setting, beautiful cut... for your future wife. But suppose instead of doing all of the above, you simply, on a whim, walked into "X" Jewelers in a seedy part of town and said, I want that one; it's the biggest one... so the salesman boxes it up and you go home, present it to your fiancé, and she loves it, marries you and it's all roses and cake. But years later, she decides to get her ring cleaned and appraised for insurance purposes. The jeweler tells her that it's a poorly cut piece of crap with a big hunk of black carbon inside... your wife... she's a bit upset, but she loves you like mad, so it doesn't matter in the end... Still, though, wouldn't it have been better to do your research?