This incredible ring dates to the late 1800's and contains a very clean, old mine cut diamond with an approximate carat weight of .45ct.
The ring is crafted from 14K yellow gold (not marked, but acid tested). This style is known as a Belcher setting; this one is a bit unique as it has four round holes in the setting (two on the top and bottom near the stone and the other two on the band). The band measures slightly over 2mm at the back and 7mm at the front. It weighs 3.4 grams.
The diamond measures 4.25mm x 3.87mm x 3.47mm and it is very white and clean. I can see no inclusions under the loupe.
This beautiful ring is in excellent antique condition. It is a size 5.5 and would be sizable by your jeweler.