Here is a strand of black diamonds. I bought the diamonds and threaded it myself. I had the diamonds tested by 2 jewelers and they are definitely diamonds. Although, I cannot tell much more about them...if they are natural this color and so forth...
I was thinking of getting a black diamond stacking band to go in between my white diamond ones. Of course, that's after the rose gold, tsavorite, alexandrite and ruby stackables that I've already added to my wish list. The list never ends...