If you're not familiar with the diamond industry, you may want to read Diamonds are Bullshit (or watch this less formal video.

I don't mean for this to be offensive, but I've always disapproved of the idea of purchasing diamonds, especially for an engagement.

There's a lot of abuse, fraud and mistreatment that happens throughout their production and distribution (then again, this is true for a lot of industries...). From a physical standpoint, it's x thousand dollars for a shiny rock (money that could have been used to do good). I get that people see it as a symbol of love and that it's reasonable to pay that amount of money for the symbolic meaning you get in return. I just find it odd that people derive such meaning, given the realities that exist beneath the surface.