Where can I exchange excess runes?

[h750731]

Where can I trade or exchange runes of one type for runes of another type in the game? I have way too much Mind Runes for example

[xerxes]

New Kordar (between arliana and grotland, underground). By the hammer the guy exchanges runes. gives less than 50% of the other.

Keep a 40 magic, mind and might runes to maximize rune mage's abilities and other skills.