Anna + Nina Anna + Nina Gold-Plated Black Onyx Gemstone Necklace | Luxury Gift | New In | Bring timeless elegance to your jewellery collection with the black onyx gemstone necklace by the brand Anna + Nina. Crafted from gold-plated sterling silver, this refined necklace is strung with polished black onyx gemstone beads for a sophisticated finish. Designed to be worn alone or layered with your favourite chains, each piece is naturally unique thanks to the subtle variations within the stone.