A nice example of plancheite on/ in quartz, from recent finds int he Republic of Congo. This piece consists of a vug lined with quartz crystals; if you look closely you can see small orbs of included plancheite.  There are saw marks on the back, these pockets are basically found embedded in a quarry wall made from a very hard, quartz rich rock.  The local miners excavate  them in very large chunks, and then I have to cut them down.... first round in Congo to reduce shipping weight, then second round in the US to make it look decent.