think about it, Pearls can be made within months to a few years. pearls aren't formed by complex geological processes, they are grown by another living thing. its entirely possible that pearls in SU are a working class that is mass produced to serve the other gems.that might be why Pearl loves Rose so much, she saved her from what was essentially slavery.

Huh… kind of like the hair…

And yeah, I think it's going to get super weird when we start seeing other rubies and amethysts and the like. I suppose the question is if they'll look exactly like the others, or have minor differences that set them apart.