A person such as rockhound, lapidary, bonehead or mineral collector that licks rocks to bring out the color potential within the rough stone. Wetting a rock shows what the stone might look like once polished. Often a rockhound will become so excited at a rock or gem show that they start madly licking rocks, hoping to discover the hidden beauty beneath the rough, unpolished surface. To the other people visiting a gem show this activity can seem very odd, inappropriate, gross and even obscene.
"WHAT in the world is that freak doing over there!? He keeps picking up rocks from the ground and LICKING them like he thinks they're food! Yuck!"
"oh, yeah.. that's just that crazy rockhound dude named Mark. He's a rock-licker."
"Man, that bonehead rock-licker has stinky breath and rotten teeth! I think I'll pass on looking through the bucket of opal he's been pawing for the past hour. "