This is quite a bargain. It's a lovely cluster of rose cut diamonds, and the ring is circa 1780. The shank is 18 carat, unmarked but tested, yellow gold, but the diamonds are closed backed and set in silver, as they always were at that time. The center diamond has a span of .33. Of course we can not weigh rose cut diamonds as we would weigh modern stones, and the only way to really weigh a diamond, would be to take it out of its setting, which of course, in a ring this old, I would not do. The diamond clusters, together, measure about 3/8 of an inch in diameter. This ring, a size 6 and 1/2 to 6 and 3/4, is in very good condition, and it appears to be all original. It could be sized by someone who is used to working with antique jewelry. It weighs It weights 2.2 grams. This is a rare chance to get an early diamond ring at a reasonable price.