I just don't get it. Who cares what the source of a diamond is? Isn't the point of a diamond its beauty in the eye of the beholder? If I had a big diamond I would definitely want the cheapest one possible with a visual aesthetic I like. Fortunately, my wife and I don't like diamonds and we have purple sapphires in our wedding bands.
At any rate, at least we can rest assured in the knowledge that if it weighs the same as a duck it is definitely a witch.