Woodbridge Antiques has dated this piece to the 1920s.
Maker's marks are also visible for HC & S.

Lovely antique ring in great condition.
Hallmarks: Birmingham 1916
Measurements:
Ring Size: P
Width of band at top: 1.1 cm approx.
Width of band at base: 2.8 mm approx.
Weight: 4.5 grams approx.
Woodbridge Antiques has dated this piece to the 1920s.
Specialists in quality antique silver, fine jewellery & accessories
You can view the stock and full dealer information on the Woodbridge Antiques Profile Page