There aren't specifics with the Gems, they are generalized enough so your Game Master can properly interpret how they should fit in the game, however if there is a conflict it would again fall on the Game Master to decide how to implement it. Keep in mind, the thrill is knowing how random they are as some Gems may not go the way you intend / hoped as what may favor one may not favor you.
I can see things getting out of hand rather swiftly in that direction. Might I suggest that 4th and higher gems provide the same level of benefit as 3rd?
There's still something to work for that way, but a character who can afford to get up there isn't overwhelming those who have not.
Edited: daishain on 2nd Mar, 2017 - 6:19pm
That could help JB, perhaps we start seeing events and opportunities that can benefit the character in indirect ways? There would need to be some caution in this direction of course.