Instructions
Navigate your character to the town train station. Consult the map menu if you need help locating it.
Look for a small pile of crystals near the train station. Once you find them, you will be allowed to enter "Prospecting Mode." Press "A" when prompted to enter "Prospecting Mode."
Follow the color clues while prospecting--green means cold, and red means hot. Locate around the crystals that turn your prospecting detector red and press the "A" button on your Wii-mote to dig.
Return the pizza oven stone to Chef Gino and reconstruct his pizza oven.