I HAD THIS MADE FROM ALUMINUM SOME YEARS AGO FOR A 300 GPH PUMP. WE USED THIS JET UNDER WATER TO BLAST AWAY ABOUT A FOOT OF HARD SAND AND MUD TO GET TO SHARK TEETH THAT WERE STUCK TO THE BOTTOM. IT WORKED GREAT AND WAS A LOT OF FUN. I THINK IT WOULD WORK FOR GOLD MINING AS WELL. SORRY NO RETURNS ON THIS. THANKS FOR LOOKING