Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Bad quality

My family eats pizza at least once a week. Its quick, easy and customizable. A big problem is getting the bottom crisp so I heat my oven to 425 with the pizza pans in it in an attempt to crisp the bottom. The heat from a stone should crisp the bottom not unlike a pizzeria oven. I knew i needed a stone so i bought this one. In order to properly use, it should be in the oven as it heats as to not "shock" it with a sudden heat change. The first time i put it in the oven and heated it, i heard a pop from the oven. I went to check on it and it cracked in half. The oven hadn't even made it to 425 yet. I was surprised because the core temp of this stone shouldn't be high enough to crack and yet it did. This means there are flaws to it, whether it's air or impure materials. I haven't bought a new stone yet but i am planning on getting a different, more expensive stone.