NEW IDRIA, Calif. -- Just south of the San Francisco Bay Area, a forgotten ghost town is drawing a handful of people mining what may be the rarest gemstone on earth, but is also awash in a highly toxic heavy metal that can wash down into California rivers and San Francisco Bay.

New Idria is the name of the remote abandoned mining town about 60 miles south by southeast of Hollister. For almost 150 years hundreds of men labored to haul out mercury, which was initially used to separate gold ore by the 49ers.

The mines – and the town – were abandoned a generation ago, but high levels of mercury are now gushing out of the more than 80 miles of tunnels. During wet years the toxic waters flow into the San Joaquin River, which drains into the Delta and then the Bay.

In addition to the mercury, asbestos and sulfuric acid has also been found in the waters, according to researchers.

“Most of this stuff was locked deep in the earth,” said Stanford University earth sciences Professor Gordon Brown. “And by deep, I mean several miles down.”

One of the few residents of New Idria, Kate Woods, lives amid the toxics she has tried to get cleaned up for more than 20 years.

“It’s ghastly,” she quipped, looking at a rust red creek running through the handsome California countryside where abandoned town of New Idria sits quietly away from most environmental activists.

Woods and her brother have a mining claim on hundreds of acres of the land around New Idria, where they prospect for a cobalt blue gemstone called Benitoite, California’s official gemstone and perhaps the rarest on the planet.

Despite the conditions, Woods says she’s staying .

“You couldn’t blast me out of here,” she remarked. “I’m not going anywhere.”