You can indeed, or at least a fair few of them. BUT most 'new' miners won't because they don't do the surface mining, just the deep core mining which liberates only minerals. I still do the old style mining when I'm out there to easily fill materials as a by-product of the activity. A little like collecting manufactured components after a fight, or idly scanning other ships/wakes when at a station.Saying that, more variation would be nice. I suppose you can also get the surface materials when mining. There is one other variation.