These are test beads for Moretti's "Special" colors. All of their yellows, oranges, and reds fall into this category.
One of the things that enchants me about glass is what happens to the glass when you melt it. Opaque colors may become transparent or change color; transparent colors transmit the light from the flame like a fiber-optic cable. Reds and yellows show a dramatic color change, with yellows becoming cherry-red in the flame, and reds becoming black. Besides being really neat to see, the color change helps me to know how hot the beads and the glass rods are. I don't want to pick up something hot and get burned!
