Question about gemming T12 Tank gear

[Gygax]

I just bought the Chestguard & Legguards of the Molten Giant to replace my 359 ones, http://www.wowhead.com/item=70945 , http://www.wowhead.com/item=70942 , Should i use hybrid gems Like Parry/Mastery & Mastery/Stamina to get the socket bonus or just gem straight up yellow Mastery gems, Thanks

[Bigbad]

red: parry/mastery blue:mastery/stam yellow:mastery in general. If you tank 25mans you might want a little bit more stamina and it also depends a little on the trinkets you use

[Apop]

I usually play it safe and gem hybrids. If youfind yourself in a scenario where you need more stam of mastery (close to one of the several mastery softcaps for example) sub in pure gems where relevant.