In reality , it was sand . Sand used to make the finest glass . After the war , the Barcid king had ordered that no glass was to be given to outsiders at any cost . Thus , over the years , glass had become scarce and the process of glass making lost to the world .
Question: What may happen if the King does n't allow outsiders to have glass after the war .
The answer to the above question:


Glass will become scarce to everyone