A group of four ruby rings

A group of four ruby rings, late19th/early 20th century, comprising: a 22ct gold ring set with a circular-cut ruby between two cushion-shaped diamonds, size M, British hallmarks; an 18ct gold ring set with a cushion-shaped diamond between circular-cut rubies, to a shank carved with scroll decoration, size Q1/2, British hallmarks; a gold ring of knot design set with a circular-cut ruby, size O, stamped 585; and an 18ct gold ring set with a cushion-shaped ruby, size K1/2; British hallmarks