Vintage Silver Malachite ring

Vintage Silver green Malachite ring Tiny dainty ring with lovely unusual marbled green stone. Couldn’t see it in life but there’s a blue spot in the photos. I think this is malachite: opaque dark green stone with inclusions. Very small size. Thin band. Can see it’s a bit wonky rustic. But lovely detail in the deep setting and rope twist frame. 7x6 mm cabochon. 1+ mm deep setting. 1+ mm wide Y-band. Size 4. New. Vintage. C. 1970s. No visible hallmarks. But I believe it’s genuine silver made in Mexico. Many of our rings with hallmarks have this type of band and rustic look. Note: It was tarnished from storage and I polished it easily with some toothpaste.