New vintage carnelian acrylic ring

New vintage carnelian acrylic ring C. 6 8x15 mm cabochon estimating 4-5 mm tall (hidden in setting) +2 mm band width 7 mm tall frame (not including gem) Unusual minimalist modern find! One of the beautiful examples of 1970s design! Polished Rusty red brown. Inclusions: Originally thought it was a semiprecious gemstone like Carnelian, Agate, Jasper, “Red Jade” but I think it’s acrylic or lucite. It’s warmer, lighter, smoother than expected of real stone. New vintage c. 1970s. Acrylic ??? (it’s really hard for me to tell!) Probably from Asia. No visible hallmarks. Probably gold plate / costume. Group photos show others in the collection.