The 2006-S San Francisco Old Mint Proof Gold Coin is a highly sought-after commemorative gold coin from the United States Mint. This coin is made of 90% pure gold with a fineness of 0.900, and contains a precious metal content of 1/4 oz. With a beautiful proof strike type, this gold coin is a valuable addition to any collector's or investor's portfolio, showcasing the intricate craftsmanship and historical significance of the U.