Deco Interiors has dated this piece to the 1930s.
Set on 9 carat gold band. Hallmarked "9ct" and "PLAT" with maker's mark.

Size M½ (16.92mm inside diameter).
Box photographed for display only; please indicate your preference of: antique ring box; modern black velvet ring box; modern leatherette ring box; or octagonal antique style box upon enquiry or purchase.
Tracked and insured postage for this item is £7.50 to UK; and £14 internationally.
Deco Interiors has dated this piece to the 1930s.
Deco interiors, windsor house, moreton in marsh
You can view the stock and full dealer information on the Deco Interiors Profile Page