How should I gem my gear?

Moonkin Gemming Basics:

Red: Runed Scarlet Ruby (19 SP)
Yellow: Veiled Monarch Topaz (9SP/8Hit) until hit capped. Reckless Monarch Topaz (9SP/8haste) if you are hit capped already.
Blue: Purified Twilight Opal (9SP/8spirit) NOTE: Only need two of these to meet meta reqs. After your two for meta reqs, Runed Scarlet Rubies or Reckless Monarch Topaz go in any other blue sockets (which gem is personal preference).
Meta: Chaotic Skyflare Diamond (21crit rating/3%crit strike damage, Requires 2 blues)

Please understand that this is simply a basics guide. Not all moonkins, especially the more progressed ones will follow this to the letter, as sometimes, circumstances dictate so. This is just a basics guide that should always net positive results. Please note that this assumes Rare quality (blue named) gems, that should be easily obtainable from the Auction House, or via your own guild’s JCs. Epic gems follow this same basics, just with higher values placed on the gems.

If you are a jewelcrafter then your blue sockets will be different. Use Runed Dragon’s Eyes for your two blues. Since they are prismatic gems (thus matching any socket regardless of color), and you can have up to three in your gear, using them to meet the blue socket requirments will net you better dps than having to use Purifieds. The 27 hit gem works as well if you need the hit, but if you can manage to cap through other gear etc, then the Dragon’s eyes will be the best gem for that slot.