Do elemental gems in Torchlight 2 have secondary effects other than direct elemental damage or elemental armor?
I am referring to poison, fire, ice and electric gem and try to understand which of them are better-
Each element has its own attack side effect, which has a chance to occur on each hit. Some of them are hinted at in the loading screen tips.
Note that these all have a chance to occur on elemental attacks from any source, including skills. Elemental gems give you these effects only as a direct consequence of giving your weapon an additional elemental attack type.
As far as I know they don't have any further effects. The idea behind finding the right one for you and your character should be the rest of your skilltree/items. This is because the gem's dmg is affected by skills/items. As an example: if you skilled 40% poison dmg, you'll get 40% more dmg from poison gems in contrast to the other elements.
If that does not really answer your question, feel free to give me further details ;)
edit: see comment - I forget about so much because of all these new games :D