Noob question: encrusted lodestones?

I seriously can't get any of these to drop. Spent more then an hour today outside heros' audience and only got 1. I managed to scrap one of another player but thats all I can find. So far I only know that Sand Elements drop them, but is there other mobs that drop them too?

Are you getting them for a collector??

Because, if you are, seriously think about what you are getting for the amount of time and thought put in, if you can get said item elsewhere, etc...

Personally, I hate collectors. They must be ripping you off of quite a lot of money; they stand out in the middle of nowhere, unarmed, with thousands of hydras running around

They are good fun. I like to use them as quest merchants.

Get me X item, i give you Y item, you get xp along the way and enjoy yourself.
Sell Y item to merchant, find a new collector. Repeat.