Olivetta Lab Diamond Necklace (1 1/2 ct. tw.) - 18K White Gold. Scattered and shimmering lab diamonds evoke a subtly floral feel in this graceful pendant. Wear it on its own for a dainty look or stack it with other necklaces for a bolder look. The length of the chain can be adjusted to 16, 17, or 18 inches to suit individual preference.