This 18K ruby and diamond ring is a semi-mount. The oval ruby is a created stone it's measurements are 5.61 X 7.65mm, which equals 1.15 cts. The princess cut diamonds are all channel set in double rows in an invisible set, with (6) on each side approx. 1.8 - 2.0 mm totaling 0.48 cts in TDW. This piece is a custom piece.