This lovely Diamonds in Rhythm® couple's necklace features two entwined hearts, one edged in black diamonds, which cradle two diamonds that shimmer as they move. You may personalize with two engraved names. Black diamonds are treated to permanently create the intense black color. Most natural gemstones pictured have been subject to an enhancement process or treatment (e.g. heating, oiling, diffusion, waxing, etc.), which may not be permanent and may require special care. Generally, most treated gemstone jewelry should only be gently cleaned by rinsing in warm water and dried with a soft cloth. Please refer to the FAQ section below for more information about gemstone enhancements and special care recommendations.