When the pinch pots were bisque fired and glazed (but not glaze fired), each child chose a marble to drop in. I asked the children what they thought would happen to the marble-- the answers were hilarious. Lots of explosions and disappearing acts. What a great science lesson on how materials can change!
The children were in awe when they were allowed to handle their finished pinch pots, and I get asked daily when they take them out of the display case and home.
Some helpful hints if you're going to try it:
1) keep the interior color light so that the colors in the marble come through
2) make sure the pinch pot stays small so that the melted marble covered the entire bottom of the interior
3) if you have enough marbles for each child to put two in, give it a try!