Head on over to the Bazaar after defeating the Imprisoned for the second time to find Sparrot, the fortune teller, missing. Speak with the speech-bubbled man over at the restaurant to learn that his crystal ball broke.
For now, he is just sitting at his house on the eastern side of town. You can get there by following the path around Gondo’s place.
Go inside and speak with Sparrot to be recruited into finding a crystal ball. Fly over to Eldin Volcano, landing at the “Temple Entrance” Bird Statue. There, go west and reach the upper ledge by using the air vent.
Look above the temple and Clawshot over there. Examine the crystal ball atop the pedestal, then send Scrapper to pick it up.
Go back to Skyloft and go to Sparrot’s house. Speak with him for your rewards.