EUC MCM black with one Diamond minimalist adjustable cocktail ring

EUC MCM black with one diamond minimalist adjustable cocktail ring Gorgeous rare find! Used some in the 1970s-1980s during the boom. Used less after. 🤣 MCM minimalist modern style. Classy elegance and bling then. Love the obelisk of black (faux onyx? resin?) with the one sparkling faux diamond / rhinestone / Crystal. It’s a men’s ring style and masculine design trend that was popular then. Still looks gorgeous now! And equally attractive for women which is why it’s in this category! 🤣 EUC vintage c. 1970s-1980s. Goldtone metal. Can’t remember if it’s gold plate or not. Only hallmark is “(c) AVON” Size 6-7 comfortably