Long known as the "Queen of Gems," pearls possess a history and allure far beyond what today's wearer may recognize. The Pearl has long been loved, praised, desired and flaunted. Throughout much of recorded history, a natural pearl necklace comprised of matched spheres was a treasure of almost incomparable value, in fact the most expensive jewelry in the world. Before the creation of cultured pearls in the early 1900s, natural pearls were so rare and expensive that they were reserved almost exclusively for the noble and very rich. Onyx has served as a worry stone and material for rosary beads for centuries. Crystal healers believe that it has the ability to soothe fears and worries, to control to overwhelming emotions. They say it can help a person maintain a positive outlook while awaiting the result of a source of anxiety. They also recommend it for improving concentration and devotion.