Follow on : I did 7 of the 49(on both sides of planet) and found 2 different types of geological.
I guess that is it ? or 3 or more on same body possible but very rare ?
Have to admit, to date I've been lazy and the most different sites I've visited, was two on a planet. As it happened those two were both the same but I hereby resolve to do a proper survey on a couple of rocks and let you know.