Borosilicate art marbles are made using a glassblowing torch. Clear & color rods are used mixing and layering the glass to achieve different patterns and style. Also pure gold and pure silver metal are fumed onto the glass to create a variety of colors. This process of fuming is done in the torch by introducing the metals to the flame by using a glass rod. The metals will stick to a hot glass rods and then putting the metal in the flame allowing it to “fume” off onto the piece of glass being made. A technique originally used by Bob Snodgrass.