Core Viewpoint - A customer reported issues with a gold pendant purchased from Chow Sang Sang, raising concerns about its gold content and quality after it showed signs of wear and contained other metal elements [2][10]. Group 1: Customer Complaint and Company Response - A customer, Ms. Li from Qingyuan, Guangdong, found her newly purchased Chow Sang Sang gold pendant scratched and discolored after one day of wear, leading her to question its gold content [2]. - Chow Sang Sang issued a statement on February 3, acknowledging the customer's concerns and indicating that they are actively addressing the issue [3]. - The company's customer service confirmed that their gold jewelry meets national standards, with a gold content of no less than 990 parts per thousand (‰) [2][4]. Group 2: Gold Purity Standards - The national standard for "foot gold" (足金) requires a minimum gold content of 990‰, which is the threshold for official recognition as "foot gold" [4][5]. - The remaining ≤1.0% of the alloy may include trace amounts of metals like silver and copper, which are added to enhance hardness and prevent deformation [5]. - The presence of trace metals such as iron, silver, and palladium is permissible as long as the total impurities do not exceed 10‰ [5][8]. Group 3: Testing and Verification - Ms. Li's independent testing revealed varying gold content across different points of the pendant, with the highest being 96.21% and the lowest at 64.37%, indicating a significant discrepancy [10]. - The testing method used by Ms. Li was X-ray fluorescence, which is a common non-destructive testing method but has limitations in accuracy for deeper layers [11]. - For more definitive results, the fire assay method is recommended, although it is destructive and time-consuming [11]. Group 4: Regulatory Involvement - The local market supervision authority in Qingyuan has intervened in the dispute, facilitating communication between the customer and Chow Sang Sang [12]. - The authority suggested that the pendant be sent to a professional third-party institution for formal verification of its gold content [12].