I'm still new to the game but I thought I might add what I've learned. Below will be a list of ore locations as I find them. 


Golden Field directly outside of the Chroland Capital where the Lvl 21 Mammoths are is a good deposit.  Several locations of the ore in a cluster. You can't miss it.

There is also a bag here that spawns approximately every 15 minutes which you can get runes from.

There are two spawns of a boss mammoth which drops items you can use around its' level.

The Buy price on the order sheet of mithril fluxuates as everything.  So far it ranges from 3s-5s which can make you some good money depending on the time you put in.


-102,2590 is two spots for agate, right next to the Lvl 19 Mantis and Lvl 20 Tangela.  Also has a blank pant for crystal growing right by them.


In game name is speeces, on server 31 Concealed Forest.  Ask me anything and I'll try to help.