Gold Ring Set With A Natural Burmese Ruby circa 1930

18-karat gold ring. It is set with a natural Burmese ruby surrounded by old-cut diamonds.
The ruby comes with a certificate stating its natural origin, no heat treatment, and provenance: Myanmar (Burma).
Stone weight: 5.20 carats.
Diamonds weight: approximately 1.20 carats.
Ring weight: 4.6 g.
Adjustable ring size: 55.
Made circa 1930.