If you are getting diamond graded by psa, check that they don't wrongly describe them as onyx. Maybe @jupityr can have them add 1/1 diamond to their database
Word. There's also apparently a bunch of whiners on reddit claiming the diamonds aren't "real" cards and aren't part of the set. @jupityr needs to set these fools straight.
I'm not sure anything I said would make much difference either way, but happy to share my perspective.
When it comes to the Diamonds, I can see it both ways. Some may feel they need the Diamond version to truly complete the set or "rainbow". For others, only the Gemstones found in packs "qualify" as part of the set. You see a lot of that same sentiment in the TCG and sports card world with promo cards and other special cards that can only be obtained through special access, convention exclusives or contests.
With all things, it probably comes down to the individual and what they deem as being important to them. The Diamond Gemstone Refractor is certainly a "real" card, but whether or not someone needs to own one to complete a Gemstone set of a particular card or groups of cards is really up to them.