One of the largest gold nuggets found in modern times is going on sale in San Francisco. The 2.7 kilogram gold nugget was found in the historic gold region in the Butte Mountains. The nugget will be sold this week during the San Francisco Fall Antiques Show and is expected to fetch $350,000. Large gold nuggets can sell for up three times the melt value.

Many giant gold nuggets were found in the region during the 19th century Californian gold rush, including a 24.49 kilogram nugget in 1859. Local experts believe this recent find is the largest in the region for decades.

The local man who wishes to remain anonymous found the nugget with a simple metal detector. Prospecting for gold on public lands is legal in most U.S. states with the finder able to keep any sale proceeds.