you gotta do the "Rune Mysteries" quest. (extremely easy, mabye 10-20 mins)
The you can go to rune alters from multiple places and mine it. A very cool rock that everyone can mine at the same time.
(it looks like a giant pillar and there are 4 total.)
The last I heard they range from 5-20 each for non-members
And about 10-30 each for members.
Hope I helped.
Pwnt you have...
Add on Xbox live if your into Halo. Just say ur from supercheats, c ya there.