The tape shows the woman withdrawing $9,000 from the bank to pay for the bar of gold.
The woman had been saving the money to make a down payment on a house.
Authorities say two suspects approached the victim in a Mancaster mall.
"She dropped them off. And when she went to cash in the gold bar, they told her it was fake," said Det. Miguel Torres, L.A. County Sheriff's Dept.
Investigators believe there are a total of three suspects involved.
If you have information, call the Lancaster Sheriff's Department at 661-948- 8466.