A small hint for mining
Anyway, the small hint (which is just for those you you who hadn't worked it out)
Use one weapon only, a fast projectile works best just for ease of targeting the rocks. Multiple weapons may destroy the mineral with the rock, single weapons leave the mineral nice and intact. I'm thinking same deal for shipwrecks as well, but haven't tried it.
Now if you'll excuse me I'm going to take this cargo hold full of gold to.... somewhere that will pay decent money for it (hehehe almost a spoiler).