Pearls often referred to as ‘queen of gems’ are formed within the mantles of oysters and molluscs. Generally, perfectly circular shaped and iridescent pearls are the most prized and expensive pearls. The most expensive pearl necklaces in the world are formed of such rich individual pearls varying in sizes and in combination with diamond, emerald and other precious stones. These exorbitant necklaces are epitome of exceptional royal provenance, unrivalled quality and exceptional rarity. These expensive pearl necklaces, some of which are centuries old, worn by the royals still have the charm and elegance unmatchable to any modern embellishment. Have a look at these timeless beauties below.