This stunning sterling silver art deco necklace features an arrow shaped central mother of pearl gemstone with two half moon shaped black onyx stonesthis chain is 45cm long with a 3cm extenderblack onyx is a member of the chalcedony family and has been used in jewellery for centuries most notably in ancient cameo jewellerymother of pearl also known as nacre is an iridescent blend of minerals that are produced by oysters and some other molluscsblack onyx informationnumber of stones 2sto