Charged Lodestones.
The BEST way to FARM them is to do events in maps where the Charged Lodestones and Cores are the rewards.
When there is not a map where these are the reward, the NEXT best way to farm is to kill high level Sparks and Air Elementals in Malchor’s Leap.
Finally, you can also kill Dust Mites and Dust Mite Twisters in Silverwastes … AFAIK, they still have a chance to drop them.
The BEST way to get them overall is to simply earn gold and buy them. The good part is that very few people are after Mjolnir, so as more Charged Lodestones enter market from map rewards, the price goes down since demand changes little.
Do events in the map that is currently rewarding Charged Lodestones as part of its Map Bonus Reward. (As of writing, this week it’s Straits of Devastation). Also, do Crucible of Eternity whenever opportunity arises for chance to drop Cores and Lodestones.
http://wiki.guildwars2.com/wiki/Map_bonus_reward
Save all the Cores you come upon and transform them into Lodestones using the Mystic Forge.
http://wiki.guildwars2.com/wiki/Charged_Core
http://wiki.guildwars2.com/wiki/Charged_Lodestone
Or, just Farm Silverwastes or any other profitable PvE map and buy cores/lodestones on the TP with Buy Orders.
Thief – Duelist | Ranger – Strider | Engineer – Technician |
Elementalist – Spellweaver | Necromancer – Warlock | Mesmer – Trickster |