A great never out of the box (altho the box took a toll in the cabinet!) KORYO Artisan Brewing Mug that was offered thru Rishi Tea several years ago. Love the shape that looks like a mushroom! Great way to brew loose tea with a tea infuser. Free of toxic heavy metals such as lead oxide, cadmium, glass or boric acid that are often found in modern pottery. The natural crackle glaze is created with wood, herb and tea ash, weathering stone, surface clay and limestone - all organic materials. With that in mind - please only hand wash and do not use soap or detergent.