The Discovery Science Channel series How It’s Made goes behind the scenes to show how colorful marbles are forged from recycled glass.
People have been playing with small balls of stone clay or marble since ancient Egyptian and Roman times. Today’s marbles are actually made of glass and used for industrial tasks, as well as games. Glass is not only inexpensive and durable but also quite beautiful to make.
The glass is melted down at high temperatures, then cut into slugs that are sent down a roller that forms them into the familiar round shape. After the glass cures, a quality check is done. Those marbles that have passed muster are reheated to add color and final polishing.