Vintage Smoky Quartz 18K Yellow Rose Gold Pendant Mid-Century Teardrop Solitaire

Vintage condition: Good (the stone is slightly loose in the setting, but secure; some oxidation; very minor wear). Very large vintage mid century (50s-70s) teardrop solitaire/statement pendant! Featuring a huge natural 35x16mm medium/deep brown Smoky Quartz, set in 18K solid yellow/rose gold. New 18” 0.8mm gold vermeil (14k plated over sterling silver) box chain included! The pendant is marked K18 (with Japanese or Chinese characters); and acid tested. The pendant measures 43x17mm The pendant weighs 6.12g