The Mabel 25cm salad bowl is made of green-rimmed stoneware. Stoneware is a clay-based material used in the production of plates and dishes, fired in the range of 1100-1300 degrees, resulting in a much more durable and less absorbent material than ceramics. Due to being fired at higher temperatures, it can be safely used in microwave, oven, and dishwasher for many years.