Guy One: Dude, last night I was Mining the Craft all night.
Guy Two: You have way too much time on your hands, don't you?
Guy One: ... *Punches Guy Two in the Face*
The extracting of a person's nasal mucus (UK term bogeys - referred as 'boogers' in the US) from one's nasal passages. The term 'mining for emeralds' came about due to the nasal materials' similarity in colour to the emerald jewel.
1. "Oops, nearly got caught mining for emeralds there!"
2. "Urgh, have you seen the bog - someone's been mining for emeralds all across the wall!"
Last night, I hung out with Haley, and I had a great time mining virgin ground. I just feel bad for the next guy because she doesn't have any gold left.