This large marble measures about 2.25 inches and is inspired by tube sponges in the coral reef. The colors that form the tubes in the marble are created by layering rods of glass and then stretching the rods into another rod that is then cut into short sections called murrine. After the murrine are formed, I put the coral reef together, pick it up on a blob of molten glass and layer the amethyst and white on the bottom. Then I finish off the marble in a graphite mold to give it a spherical shape.