Spotting the rocks is not that hard. Use an A-rated PWA for the range and only inspect the ones that keep glowing the brightest yellow even when you get closer. Some are bright yellow at a distance but fade when you get closer - ignore those.
Every ring type has only one rock shape that contains cores. Learn those. A bright yellow one that doesn't match the shape can be ignored. If you think you got one, get close and look at it - you can see the fissure on the surface, it looks a bit like the vintage LucasArts logo. Only then waste time and a limpet on prospecting.
Doing it in VR is a bit of an advantage because it is easier to survey the surroundings. Guess VR is pay to win too
