Some of these gems really need balancing and tweaks so that all of them are fun to use and able to all be used more often.
1: White gem may benefit from a range debuff, an inaccuracy factor or a cooldown (suggestion of 30-60 seconds, or using rings).
2: Orange gem should probably be able to give invincibility to projectiles, just enough so that it can be used as an anti-enemy tool, but not so that you can cheese everything like the white gem.
3: Red and blue are fine, in my opinion.
4: Light blue gem would likely benefit from a built-in attack if it doesn't have one. (I'm not entirely sure if it can be used as an attack, but being able to collect rings while attacking would be fun to use and used more often).
5: Purple gem should NOT be able to be used with an elemental shield, it makes a combination that breaks almost everything due to extreme constant jump with the bounce.
6: Green gem should be able to be held for easier use, like the purple gem.
7: I think it'd be helpful if you could reorder the gems so that you can have your favorites up front.
I'm not afraid of critiquing, go ahead and bounce your ideas off mine.