Roberto Coin "Princess Flower" .38ct t. w. Diamond Flower Earrings. Founded in Vicenza, the City of Gold in 1977, Roberto Coin jewelry celebrates the elegance of femininity, creativity and craftsmanship. From the "Princess Flower" collection, these 18kt white gold earrings shine with .38 ct. t. w. round brilliant-cut diamonds in elegant flower shapes. Post/clutch, Roberto Coin diamond flower earrings. Diamond birthstones are the perfect gift for April birthdays.