Large Vintage Sterling Silver Heart Locket Necklace

Sterling silver bright cut floral heart locket is unmarked as far as I can see, unless it is under the duckie, and tests as sterling.  It measures about 1 1/2 inches, including the bail, by 1 1/4 inches wide and it is on a sterling silver 24 inch box chain.  The weight of the necklace is 12.4 grams.  The pendant has a small ding on the back that did not show up in the photos.  It presses closed firmly but does not snap closed.