Ever since I saw that show about DeBeers and the "real" costs of diamonds, I haven't been interested in them. Cheap rocks is all they are.
I saw that show too, and I also read an article about the DeBeers near-monopoly on the diamond market, and how they established it, and their advertising tactics. I think only diamond experts would know which stones are a cut above the ordinary and have real and lasting value. The rest of us are just buying into the hype.