.24 Half-Round Diamond Earring Studs in 18k White Gold. 24 Half Round Diamond Earring Studs in 18k White Gold. These petite and sparkling stud earrings feature . 24 carats of diamonds finished in 18 karat white gold. Two (2) . 065 carat baguettes and sixteen (16) . 0068 carat diamonds create two half round shapes on each stud backing. The baguettes are set in channel bars and the round diamonds are set in shared prongs.