The engagement and wedding rings made from black gold look exotic and unusual, though they are more and more common these days. Note that if you choose a black gold engagement ring, both groom’s and bride’s wedding rings should also be made from this metal. Otherwise, it will look weird.
Pro: this metal works perfectly with pure diamonds, creating a lovely contrast.
Pro: black gold is trendy now.
Con: the black color is achieved by rhodium plating, which is comparatively easily damaged (scratched or dented). The original white gold will peak, spoiling the whole idea. You can re-plate it, but it mans additional spends.