How do you make a toothpaste marble?

Answer 1

Scrap glass of whatever colors are desired is melted in a kiln. The two colors of glass are extruded and automatically cut into soft blobs of the right size. The red-hot molten glass blobs fall onto a pair of tapered steel cylinders that rotate, spinning the blob into a round shape. As they proceed down the two corkscrewing cylinders they cool, then are sorted, and bagged.