Updated

The Oakland Museum of California is offering a $12,000 reward for the safe recovery of a rare Gold Rush-era quartz and gold-encrusted jewel box that was stolen.

Police said Wednesday it could have been the second theft from the museum by the same person.

Oakland police Lt. Oliver Cunningham says there are striking similarities between Monday's break-in and the theft of gold nuggets and other historic artifacts in November.

Museum director Lori Fogarty says the jewel box was a wedding anniversary gift from a San Francisco man to his wife in the 1800s.

Oakland city officials have said the box was valued at more than $800,000.

Another Northern California museum and a county courthouse have also been hit by gold thieves over the past year.