14k pendant featuring an oval onyx cabochon

Total Pendant Weight (g): 7.0 Gemstone: Onyx Metal Type: 14K White Gold Marks: 14K Stone Dimensions (mm): Length 24.0, width 16.0 Stone Shape: Cabochon approximate. Stone Count: 1 Stone Color: Black Transparency: Opaque Metal Finish: High Polish Measurements: Length 1.4", Width 0.7" 🌸 Pendant estimated value is $290 USD. Purchased from TRR (US) see last two photos🌸 🌸Chain has unknown metal due to no stamps, but it has not tarnished and been with me over the years. I would assumed this is silver.