My Best Friend Is A Diamond True friends are like flawless diamonds, very valuable and hard to come by. Like perfect diamonds, a true friend lasts forever, is irreplaceable, and can endure the worst damage while only coming away with a scratch or two. So it stands to reason that pseudo-friends are cheap imitations of this wonderful rarity, much like cubic zirconia. Zirconia friends, while outwardly appearing to be the same as a diamond, are much weaker and do not last.