[@Akayaofthemoon] "Ah, it's alright.  You didn't upset me, it's just that stealth is kind of my entire thing, but that wouldn't mean much if my primary ability was something just anyone could do.  Thank you Aquamarine, I feel a lot better now, and this Susntone sounds very interesting."

Hm yeah, I remembered that one gem but wasn't sure if it really counted since like you said it was a gem monster.  If a monster who was made to was able to do it but we don't see competent gems using the same ability as soon as it becomes useful, maybe Spinel really doesn't have anything to worry about.