Yeah, the only way of sharing gems there is currently in the game is doing duels and suiciding to give your friend the gems. But that lowers your KDR, and who wants that, honestly! Maybe Minecade will add a sharing system soon (Ex.: /share <player> <amount>).
That is why my kdr is like .9 XD I let my brother win most of the time and give random people gems because I had like 3000 at one Point on average I get about a 4-6 kdr on matches against teaming classes that are good/skilled players or against really skilled players I get less than that and average more about 2-3