The largest gold nugget ever found in Alaska is set to be auctioned in Texas in December and is expected to fetch over $700,000. In the summer of 1896, over 100,000 prospectors descended upon northwestern Canada after gold was found near the Klondike River. About 100 years later, in 1998, a prospector named Barry Clay—so the story goes—was moving dirt with his bulldozer along the shores of Swift Creek Mine when he unearthed a giant gold nugget larger than a softball. Clay was said to have buried the precious metal nugget beside a tree while considering what to do with it before toting it into town, and eventually selling it to a consigner directly. Today, that chunk of gold is known as the Centennial Nugget. Weighing a colossal 20 pounds, it is the largest gold nugget ever discovered in Alaska, according to Heritage Auctions, and the second largest found in the …