Based on the context and the answer, generate a question. 

Context: 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 .

Answer:

The Barcid King ordered his people , at no cost , would glass be given to outsiders after the war .



What may be the reason glass has become scarce and the process of making glass making be lost to the world ?