Unusual antiques

Exploration Stage: Crystals
From: Mario Bonmarito
Description: The mayor has asked me to do a very difficult job. He said that the gift store contributes to revenue with magical ice that creates a seasonal ambiance. Incredible story, don't you think? I don't know what form to put this on the books...well, we'll figure it out. In the meantime, will you help me find some ice with me?
Completed: You have found the magic ice. Thanks to you, I feel better. Is this something of value? For now, let's list it in a separate column as a Thanksgiving artifact. Oh, the math is going to be complicated! Hopefully the mayor will be pleased...