Diablo – How to get better gems

There are a few Barbarian skills that charge at enemies and generate fury which should be used often. Leap is one you gain fairly early on, and you can even use it to jump up and down ledges or across chasms where other classes have to run around. You should generally be running ahead of players rather than lagging behind.

Also remember that you can build up Fury just by attacking things like crates. Keep your fury high even without any enemies around so that you're ready to go when you do find something to kill.

Barbarians (and Monks) get a passive 30% damage resistance to make up for their melee natures, and tend to have higher vitality and health than the other classes. Against many enemies, it is the right thing to do to just jump in and start causing havoc. Barbarians are good at distracting enemies while their teammates do damage, so try to focus on that rather than claiming the final blow. You get full experience and drops whether you're the one landing the finishing hit or not.

I found both my first socketed item and my first gem in Act II after I

killed Magdha.

However, both @Sterno and @OrigamiRobot found gems before the activity above - so far, it seems Act II is the only real concrete limitation so far.

However, both OrigamiRobot and @Resorath confirm a similar experience (a gem dropping off the activity above). It seems that a gem will always drop from said mob. It does not seem a socketed item drop is guaranteed, though.

It's a few more quests until you find the Jewelry Artisan, Covetous Shen, but it is shortly thereafter in the same Act. You can find gems before him, and before the activity above.