Cal. Penal Code - PEN § 343. Section 343.
Every person who purchases gold bullion, gold bars or gold quartz or mineral containing gold, who fails, refuses, or neglects to produce for inspection his register, or to exhibit all articles received by him in pledge, or his account of sales, to any officer holding a warrant authorizing him to search for personal property or to any person appointed by the sheriff or head of the police department of any city, city and county or town, or an order of a committing magistrate directing such officer to inspect such register, or examine such articles or account of sales, is guilty of a misdemeanor.