Combine the warmth of handcrafted, embellished stoneware with the performance of vitrified china. Each piece is fired twice for superior edge strength and impact resistance. Given its low absorption rate, it s safe for the dishwasher, microwave and oven up to 400 degreesF.Available in Blue and Gray. Set of Four. Twice-fired ceramic. Strength and resistance of vitrified china. Safe for the dishwasher, microwave and oven up to 400 degreesF. At Frontgate, our primary focus is quality. We guarantee that every product we sell will stand up to the supreme test our customers satisfaction. To learn more about our policies, visit our Shipping & Processing, Returns & Exchanges and Warranty & Price Guarantee pages.