1n. a mining area or claim appearing to have attractive mineral deposits; a site that a prospector works.
1859  At this place I prospected and found some excellent prospects.
1928  On his way from his "prospect" to the "outside" this man saw his fellow men for the first time at the mines.
1958  Black Crow Mines is exploring a 21-claim gold prospect in Davis Twp., Sudbury area, Northern Ontario
2n. the quantity of gold panned on a prospect.
1860  Two bits to the pan is an excellent prospect.
1870  On French creek the Cosmopolitan co., on Thursday last, got a prospect of two ounces to nine car-loads of dirt, although their tunnel is not yet fairly in the channel.