Come in various sizes. When hit they split into two parts. If the parts get too small they turn into free floating 'Minerals' (or vanish if contaning nothing of value).
Minerals can be picked up by ramming them.
Minerals are quite small but show in colour on the radar. Use radar to get close then slow down and aproach by eye.
Rocks have individual 'mineral composition'. The effects their apperance.
When a rock splits it's components are not divided equally. They 'concentrate' in the remaining parts. Enables the creation of pure free floating minerals for mining.
Regardless of composition the radar displays all rocks as dark grey.