This exquisite necklace with pendant is enhanced by the use of crystal, a highly reflective and dispersive form of glass which has a lot more sparkle. It was originally made with lead oxide. The technique of making such glass has been known for several thousand years. Now glass with the same the same attractive qualities can be made without the use of lead. Facetted crystal glass stones and beads produced by Swarovski and Preciosa are widely used in jewellery and companies such as Dartington and Waterford produce drinking glasses and decorative items.