Sterling Silver and Black and White Diamond Heart Pendant Necklace (1/4 cttw), 18" Sterling silver necklace with stacked heart pendant featuring black and white diamonds on either side of front heart Black diamonds may have been treated to improve their appearance or durability. All our diamond suppliers confirm that they comply with the Kimberley Process to ensure that their diamonds are conflict free. Imported Carat weight listed is the total for all stones.