Baked marbles recipe Put your clear marbles in a pie pan. Bake them in a preheated 500 degree oven for about 20 minutes. Have a metal bowl with ice cold water ready. Remove your marbles and immediately dump them into the water. The marbles crack!
Glow in the Dark Green Slime Glass Plugs. These clear glass plugs have a convex front that magnifies the speckled glow in the dark texture on the back side. The backs are coated with a "slime" green coloring.