The inserts at the top of the cufflinks look very much like shell, but hard to tell accurately. Both very faintly stamped 10k to rear on the cross link. Total combined weight approx 6.2 grams, each segment is 13.6mm in diameter. Stunning condition...
Measures 43mm high x 36mm wide and weighs approx 7 grams. The clasp is stamped 14k and the Diamond was tested with a Diamond tester. There are some stress fractures top right edge.