I'm not really sure of the procedure for bumping a locked thread, but I was just thinking it'd be nice to have more gems pop out of rocks, and also to have a use for them, and did a search and 'lo! I had already commented in such a thread! Unfortunately it was four months old. But here it is!
I would LOVE to see Emeralds, Amethyst, Opals etc in the game. It'd also be lovely to have them incorporated into some sort of Crystal Casting skill that allows us to create the non-plain crystals that aren't in existence yet.
Not sure what we'd do with them, but there are all sorts of resources that will need to be added to our homes and home streets ;) Perhaps colored crystals could be needed in rock summoning or firefly swarm proliferation?