What materials have been used to make mosaics throughout history?

Well, older mosaics often were made of pieces of glass or small rough pieces of stone. Floor mosaics were made out of stone. A glue like paste was used to stick the pieces onto the walls. Michaelangelo's mosaics were often made out of colored tile and naturally colored stones. He also used glass.

Ithink that c would make the most amount of sense.