I don't understand the value of diamonds, either. Nor the desire to wear a piece of jewelry with a large diamond, or several, on it.
There was a fellow that wanted to marry me once. He presented a ring with a ridiculously large diamond on it and insisted that I would wear it. No, I would not. I was ranching and putting up hay to support my family at that time and that stupid ring could have caused injury or even killed me. Figured out the guy was more in love with some image and didn't even know what that entailed.
I'm more of a pearl girl, I guess. Though pearls are quite odd, too, aren't they? And there are so many pretty stones, though. I like those and have quite a few sets of jewelry with semiprecious stones.