It shall be unlawful for the holder of a permit to conduct a public auction of jewelry or for his agents, servants or employees to sell or offer for sale at auction any jewelry to which there is not attached a card or label containing a true and correct statement plainly written or printed in the English language specifying the kind and quality of metal of which such article is made or composed, or the percentage of carat or purity of such metals. If such articles are plated or overlain, then such tag or label shall contain a true statement of the kind of plate. When precious stones are sold or offered for sale at auction, as such or as part of an article of jewelry, such statement shall set forth the true name of such stones. When imitations of precious or semiprecious stones are offered for sale or sold at auction, as such or as part of an article of jewelry, the imitations shall be described or defined as synthetic or imitations of such stones as they purport to represent. When watches or clocks are sold or offered for sale at public auction the true names of the manufacturers shall be stated in writing and no parts of the movements or mechanism thereof shall be substituted or contain false or misleading names or trade marks, neither shall secondhand or old movements be offered for sale in new cases without a true statement to that effect. Used and rebuilt watches shall be so indicated. Such card, tag or label shall remain securely attached to any such article of merchandise, shall be delivered to the purchaser as a true and correct description and representation of the article sold and shall be deemed prima facie evidence of intent to defraud in case such written statement is not a true and correct description or representation of such article sold. (Ord. No. 462, § 7.)