RENO -- Some 150 years after the forty-niners rushed west in search of riches, a new gold discovery in the Sierra Nevada is stirring excitement.
A 100-ounce nugget, found by a man last year on his property near Nevada City, Calif., is expected to fetch between $225,000 and $400,000 when it goes up for auction March 15 in Sacramento, Calif.
Fred Holabird, a mining geologist whose Reno-based company is one of the country's largest sellers of Western Americana and is handling its sale, thinks it's the largest California gold nugget left in existence.
Virtually all of California's gold fields have been thoroughly combed by miners, he said, and other monster nuggets from the Golden State have been melted into ingots for money.
While bigger nuggets have surfaced in Australia in recent decades, no similar-sized placer nuggets from California have turned up in museums, he added.
The Smithsonian Institution's largest placer nugget from California weighs about 80 ounces.
"The chances of finding something like this anymore are beyond remote. It could be one in a trillion," Holabird said.
The man was using a metal detector in an unmined ancient stream bed near the old Mother Lode mining camp of Washington when he stumbled on the nugget in February 2010.
The Union of Grass Valley, Calif., has identified him as San Francisco businessman Jim Sanders.
The so-called Washington Nugget is thick and oblong, and resembles a "squished loaf of bread," Holabird said, adding it was found in the same area where hydraulic mining was invented in the 19th century.
A lack of records makes it difficult to determine how the nugget compares in size historically, said John Clinkenbeard, senior geologist with the California Geological Survey in Sacramento.
But he said he's unaware of any similar 100-ounce placer nugget being found in California in recent decades.
While current gold prices would make the Washington Nugget worth roughly $130,000, Holabird expects a collector to pay more because of its historical value. Gold closed at $1,368.90 per ounce Friday.
"It's worth more as a collectible," he said. "No one will be melting this thing. It's one of the most important California gold artifacts that exist."