Dating to the 1910s/1920s or so, here's a lovely rose gold cocktail ring set with a center Operculum Shell (brown caramel hue) and accented with 4 faceted round diamonds (tested) and a bit of nouveau swirl. Condition is very nice with no problems I can spot. Well, I could have cleaned the ring before I took the photos but I didn't realize the diamonds needed a bit of a clean. Anyway, the ring is MUCH better looking in person that in my photos.
Metal Content is 10K Rose Gold with a Hallmark of 10K (stamped twice) on the inside of the shank.
Ring size is 5-1/2 on my sizer. Top design measures 5/8" east/west x 13/16" north/south.
Weight is 4.8 grams.
Diamonds number 4 and measure 2mm each (3 points) for a total weight of .12CT TW. Color is G-H and clarity is SI1.
Just a terrific looking antique ring!