Ross-Simons - 4.5mm Cultured Pearl, .70ct t. w. White Topaz Ring in Silver. Size 6. Glisten and gleam with this nicely priced statement ring! A lustrous row of 4.5mm cultured freshwater button pearls is nestled between .70 ct. t. w. round white topaz borders, all set in polished sterling silver. 1/4" wide. White topaz and white pearl ring. Pearl birthstones are the perfect gift for June birthdays.