This is out of date (3.3.5)
How to gem an elemental shaman? This is a quick summary list of your best options. In many cases, you can ignore the slot bonus. Exceptions include fulfilling the meta gem requirement and items with a decent bonus.
Chaotic Skyflare Diamond (requires 2 blue gems) for 3% bigger Lava bursts.
Runed Cardinal Ruby (red) recommended
Reckless Ametrine (orange) recommended
Veiled Ametrine (orange)
Rigid King's Amber (yellow)
Glowing Dreadstone (purple) use 2 for your meta
Jewelcrafters should use 3 Runed Dragon's Eye
For more detail on alternatives to the above or for explanations of when to use when try the following resources:
How to Gem your Elemental Shaman @ The Shaman Tavern
How to Gem your Elemental Shaman @ Bob Turkey's WoW Blog (pre-epic gems)
How to gem an elemental shaman? This is a quick summary list of your best options. In many cases, you can ignore the slot bonus. Exceptions include fulfilling the meta gem requirement and items with a decent bonus.
Meta
Chaotic Skyflare Diamond (requires 2 blue gems) for 3% bigger Lava bursts.
Red Slots
Runed Cardinal Ruby (red) recommended
Yellow Slots
Reckless Ametrine (orange) recommended
Veiled Ametrine (orange)
Rigid King's Amber (yellow)
Blue Slots
Glowing Dreadstone (purple) use 2 for your meta
Notes
Jewelcrafters should use 3 Runed Dragon's Eye
For more detail on alternatives to the above or for explanations of when to use when try the following resources:
How to Gem your Elemental Shaman @ The Shaman Tavern
How to Gem your Elemental Shaman @ Bob Turkey's WoW Blog (pre-epic gems)