Last week, I experimented with putting some glass ornamental flat marbles in the bottom of two pinch pots to see what would result after firing. The first pinch pot was about a cereal-sized bowl, coated on the exterior with floating blue glaze and the interior with glossy, which was also used on the rim. Several turquoise marbles were placed in the bottom of the bowl, and it was expected to win the marbles would melt into a turquoise layer on the bottom.
The colour of the marbles must have burned off or reacted in the kiln and what resulted was a very pale blue layer that resembled broken ice on the bottom of the bowl. There seemed to be something in the glass that gave a bit of a sparkle in the texture and a sort of an interference resembling frosty patches. The next time I try a solar experiment, I may use a dark glaze on the interior.
The second bowl was a small pinch pot heart, glazed on the exterior with mocked green and on the interior and rim with the glossy white. Several small purple marbles were placed in the bottom of the heart. I expected the purple would not be a stable colour for firing; instead, I was pleasant surprised to find an intense purple layer after the firing.
The purple definitely welcomes further experimentation…