Sky and Earth is cool, but a bit of a departure from their current naming.
Personally, I think Pokemon Opal and Jade would be good, with Titanium as the third.
I don't think anyone cares about rarity, but Nintendo do care how nice the names sound. Amethyst? Tungsten? No, I don't think so.
Just thinking about it, i'll take a bet with someone that the next versions are Opal and Jade. It's a big shout mind, so I'd need a big incentive.







