Here's an example of cobalt occurrence in an intrusive ultramafic (dunite):
and an extrusive ultramafic (komatiite):
There are more types of geology.
Also note that processing of laterite nickel is more costly financially and environmentally. Asbolane is the easiest/cheapest to beneficiate cobalt, because of its preferential response in atmospheric leaching. In fact this preference for cobalt leaching (instead of nickel) could be what is turning the fortunes of some of the Ni-Co laterite resources.
Sulphides are cheaper to process. But, being magmatic, are often deeper and narrower. You need to measure the resource against the methods of winning the metal in order to judge the meaning of the grade. Underground mining for example is more expensive to accomplish but can target higher grade ores, so less processing waste.
I can't find an equivalent table for sulphide minerals. These are all examples.
Hope that helps.
