yeah, that was the story. back before 1.2 they did the pure white crystals and a few peeps accidentally deleted theirs. when they put in a ticket, some of them got black core / white aura crystals as replacements. there has been a quiet clamor for this mythic crystal ever since. several data miners have turned up the black//white crystals in the code, as well as a few others that have yet to be seen in game anywhere.
all that said, I agree that this black/black concept would be most welcome. the black white would be moar welcomer