1981 San Francisco U.S. Assay Office Silver Round. Eagle and banner, ONE TROY OUNCE .999 FINE SILVER 31.1 GRAMS SILVER TRADE UNIT. Reverse MINTED FROM US STRATEGIC STOCKPILE SILVER FORMERLY STORED AT US ASSAY OFFICE SAN FRANCISCO. Beautifully toned (what would you expect?), of course. These were issued shortly after the Hunt brothers tried (duh) to corner the silver market, and these helped bring the market prices back down to earth.