@21308 Well, I doubt gems only include gemstones traditionally used in jewelry making and also include other crystals (thus Evenkite), but I get your point for sure. And yes, I personally believe that there are other gems of the same name. And I'm thinking it's okay to keep Onyx: If Sardonyx
does turn out to be a fusion between two gems being Onyx and Sard, our Onyx would've technically been made before it. I mean, think of how many people have made OCs for Ruby, Sapphire, Peridot, Jasper, Lapis Lazuli, and now Sardonyx before they were introduce into the series?
As for that, a bunch of people think that there were four leaders given the respective title as 'diamonds' due to Homeworld's symbol being a diamond and the one picture in Sworn to the Sword with four coloured diamonds; Yellow, Pink, Blue, and White, so now people are theorizing that Rose Quartz was Pink Diamond, and that this Sardonyx fellow is the aforementioned Yellow Diamond who Peridot and Jasper serve. Personally, I think it's a little to early to make such assumptions as we don't really have much hard evidence, but time will tell.