Marble (toy) Required" and "The Colbert Report". Currently, the world's largest manufacturer of playing marbles is Vacor de Mexico. The company makes 90 percent of the world’s marbles. Over 12 million are produced daily. Marbles are also made in China and may contain lead, arsenic, and/or cadmium due to the manufacturing process of old glass. Art marbles are high-quality collectible marbles arising out of the art glass movement. They are sometimes referred to as contemporary glass marbles to differentiate them from collectible antique marbles, and are spherical works of art glass. Collectible contemporary marbles are made mostly in the United States by
Elgin Marbles Parthenon, which is regarded as one of the world's greatest cultural monuments. International efforts to repatriate the Marbles to Greece were intensified in the 1980s by then Greek Minister of Culture Melina Mercouri, and there are now many organisations actively campaigning for the Marbles' return, several united as part of the International Association for the Reunification of the Parthenon Sculptures. The Greek government itself continues to urge the return of the marbles to Athens so as to be unified with the remaining marbles and for the complete Parthenon frieze sequence to be restored, through diplomatic, political and legal means. In