from

http://elitistjerks.com/f15/t29288-w...on_thread/p43/
And for JC, is it still one of each BoP gem or is it 3 BoP gems in total now ? (+ BoP jewelry)

3 in total, and it can be 3 of the same type. They also count as all
three colors at the same time, both for meta gems and socket bonuses.
Granted this is still beta but you might be able to stack three of the +spell damage gems