Millions of dollars in jewelry and gems belonging to exhibitors at a California retail show were stolen from an armored car traveling north of Los Angeles last week, authorities said on Monday.

The robbery took place in the early hours of July 11 in the city of Frazier Park as the Brink's Co vehicle was heading toward a storage facility, said Brandy Swanson, director of the International Gem & Jewelry Show, which hosts retail exhibits in venues around the country.

It was previously thought to have occurred in the city of Lancaster, but FBI officials confirmed the location. No other details were provided.

The robbery involved about 25 to 30 lockers of jewelry and gems belonging to 18 individual exhibitors at a show in San Mateo, south of San Francisco, she said. The merchandise was going into storage ahead of another show scheduled in Pasadena.

Brink's said in a press release that the missing items were worth less than $10 million, while Swanson valued them closer to $100 million. The security company could not be immediately reached for comment.

In explaining the discrepancy, Swanson said smaller exhibitors tend to undervalue their pieces for insurance because of the high cost of coverage.

Swanson said her group was working with local law enforcement and the FBI.

It is unclear how the truck was robbed, whether there were tracking devices on the lockers, or if there were security cameras on the truck or in the area, she said.

"These victims are mom and pop operators, but the value that was in those lockers is worth more than people understand," Swanson said. "That's their life. Their whole life's savings is now gone."