Fascinating 14K Yellow Gold Blue Topaz Sapphire Diamond Stud Earrings. Each great piece features one princess shaped natural blue topaz, several natural round blue sapphires and single cut round diamonds. The total weight of the topaz and sapphires is 1.44 carats and diamonds weigh a total of .12 carats. Each piece measures 3/8 of an inch wide on each side. The pair weighs 2.5 grams.