Hi, I got a 76 lb flask I purchased from a montana gold miner about 10 yrs. ago, I am looking to sell for 1,300 obo, its in a nice clean metal container with yellow top, when I got it the miner said it had been cleaned hmmm I wonder if it was cleaned of all the gold, anybody know of a simple safe way to check? Thanks, Jimmy (aka survivorjp), North Carolina.