54.00 ct. t.w. Quartz Biwa Pearl Necklace With Mother-Of-Pearl and Cultured Pearls In Sterling Silver. 18" - An RS exclusive. Our spectacular bib-style necklace features 54.00 ct. t.w. of quartz for an elegant, icy sparkle along with the gleam of mother-of-pearl, cultured freshwater and Biwa pearls. Necklace is presented in polished sterling silver.