Guardian's Alchemist Stone

*Updated for 6.1* - Philosopher's and Alchemist's Stones over the years

Vanilla

BC

Wrath

Cata

MoP

WoD

Philosopher's Stone

Alchemist Stone
Assassin's Alchemist Stone
Guardian's Alchemist Stone
Redeemer's Alchemist Stone
Sorcerer's Alchemist Stone

Indestructible Alchemist Stone
Mercurial Alchemist Stone
Mighty Alchemist Stone

Lifebound Alchemist Stone
Quicksilver Alchemist Stone
Vibrant Alchemist Stone
Volatile Alchemist Stone

Zen Alchemist Stone

Draenic Philosopher's Stone
-New for 6.1-
Stone of Wind
Stone of the Earth
Stone of the Waters
Stone of Fire

Remember, you need one of these to be either equipped or in your bag to do transmutations. Enjoy!

Defense rating gives almost as much avoidance per point than Dodge rating, at least to Paladin/Warrior, making this a very accessible trinket to both. (Not to mention it aids Block chance.)

This is good if you are an alchemist tank and you are trying to get your defense capped while in resist gear. Resistance gear has no def so you can use the trinket slots to help get more in there. There are only three epic trinkets in the game that have defence and aren't craftable, one is the level 60 styleens from BWL, and one drops from hydross if that is any indication. I use Styleen's to get to 490 defense on hydross while I wait for the shadowmoon insignia or another hydross trinket (we don't really do hydross anymore though... but we do bloodboil every week).

There is also a JC epic trinket with defence.