Great Tiffany & Co. 14K yellow gold earrings are appropriately marked as shown with Tiffany & Co., 14K, Patent No. 2423905, and "P". The patent dating back to the 1940's applies to the type of back that is a clip with a post through it. The earrings are in excellent condition and have no damage or issues. An independent Gemology Institute of America appraiser has valued the earrings at $3,500. Purchaser will receive the appraisal with the earrings. Texas residents to pay 8 1/4% sales tax or provide exemption information.