This was a rather hilarious YouTube recommendation, a geologist invites rockhounds/prospectors onto his show and identifies their rocks. Now, pretty boring, even for me, but worth it for the part where he tries to get some clues as to where this rock came from...
..."on the ground..."
More precisely?
"...in the desert..."
...
"Well, you see, we don't really want to say, be giving away our prime spot and all..."
Now I completely get it, who wouldn't, and the geologist, he sort of gets it, and the rock, it's pretty ugly, just a rock, but to them it's treasure, precious, and they'll go so far as to narrow down the area to a state, or a few hundred square miles, but more than that, well, it's just asking too much.