Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Stone cracked

Very disappointed with this product. After using just two times, the stone developed a hairline crack - rendering it useless. The stone was placed on lower rack of oven and increased temperature slowly to 475 degrees. When finished, the stone would remain in the oven until it was completely cooled. I've used stones for baking pizzas, breads, etc. for over twenty years at approximately four to six times a year. My previous stones normally lasted 5 years. I mistakenly expected high quality for higher price tag. The Old Stone Oven Corporation needs to address the quality control on this product as it did not perform as advertised.