قَوَا۩رِيْرَا۟ مِنْ فِضَّةٍ (vessels of silver...Al-Insan 76:16 ⧉). Silver vessels in this world are dense which can never be like glass, and that which is made of glass can never be silver. Thus silver and glass are two contradictory concepts in this world. However, it is a characteristic of Paradise that its glasses will be as bright as silver, and as transparent and sparkling as crystal.
Sayyidna Ibn ` Abbas said: The blessings given in Paradise have their likes in this world also, except these vessels that are made of silver, but as transparent as a mirror."