The most valuable gold nugget in the California State Mining and Mineral Museum's collection isn't in the hands of robbers, thanks to one of its unique qualities -- its weight.
That's one of the few details California Highway Patrol investigators have released about Friday's brazen $2 million heist at the museum.
CHP officials said Monday that their investigation is under way, and no suspects have been identified.
However, the most precious piece -- a 14-pound gold piece known as the "Fricot Nugget" -- remains intact, according to CHP officer Matt Radke.
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Radke said the thieves tried to steal the huge gold nugget, but could not remove it quickly enough during their two-minute dash because of its weight.
Based on the investigation, there may have been more than two robbers involved, and they're considered armed and dangerous. The robbers were dressed in black, wore hoods to conceal their faces and used pickaxes as weapons.
They entered the museum's vault about 4 p.m. after making threatening statements to a guide and curator, Radke said.
An inventory is being conducted this week to identify which pieces were taken and to determine the value of the stolen minerals. According to authorities, the unique pieces are easy to identify, which should make them difficult to sell.
The museum, which is operated by the California Department of Parks and Recreation, is home to more than 13,000 artifacts dating back to the 1800s.
In addition to displaying historical mineral specimens, the museum provides tours for local schools, conducts a Junior Ranger Program, and sponsors an annual gem and mineral show.
In recent years, the museum has fallen on hard times and was being considered for closure by the state because of budget cuts. But with the discovery of $54 million in unaccounted for state parks funds, the closure was put on hold.
Anyone with information about the robbery is asked to call (209) 356-2900.
Reporter Ramona Giwargis can be reached at (209) 385-2477 or firstname.lastname@example.org.