Crafted of Stoneware, featuring a reactive glaze. Due to the nature and hand-crafted qualities of reactive glaze, no two pieces are exactly alike and will exhibit unique variations in color and pattern. Product may slightly differ from image shown. This Blue Geometric Stackable Mug is perfect for enjoying your favorite beverage every day. Features a unique base that fits inside a mug of the same design, so if you have multiple mugs, they can be stacked for compact storage in a cabinet. Microwave and dishwasher safe. Mug holds 15 ounces.