By using the Mining profession it's possible to get Power Crystals and their Ores. Go to the Profession town via the dimensional mirror and select Ardentmill (I think it's that. The icon should have a book on top of it's portal). Once there you need to talk to the old man with a quest on the left to learn about professions. Then you drop down from there, go right until you find a short, stumpy man putting ores on a conveyor belt. Talk to him, learn mining, do the quests he gives and then you're all set. To get Power Crystal Ores after this you just need to find Red coloured gems on maps. Once harvested they have a chance to drop what you need. When you have enough you can go back to Ardentmill and smelt them together (By that point you should know how to do that).
Hope that helps!