Gemming Mastery

[towelliee]

I seen a lot of tanks gemming 67 mastery from JC and Parry/Mastery. Is this proper for raiding?

[Treck]

67mastery vs 101stamina is exactly the same relation as choosing between 20mastery vs 30sta.
So if you prefer 20mastery/30sta gems in blue sockets over 60sta, you would prefer 67mastery.
If you rather choose mastery/sta intead of pure mastery in yellow sockets, go for 101sta gems.

Both are "viable" for raiding, id personally prefer stamina tho.

Parry/mastery in one gem?
Dont see where that would be benefitial realy.
Yellow slots = 20mastery+30sta or 40mastery.
Red slots = 20Parry+30stamina (not worth it going full parry, and this gem is really only worth it if the bonus is decent)
Blue = 60sta or 20mastery+30sta.
If you meant it by socketing for parry/mastery to get setbonuses, id personally only go for partially blue gems, but if the socketbonus is good wnough, definately.