There are some kitchen appliances that do not look so particularly amazing. They just cook the food. But the new Zisha Slow Coker made by Sunpentown uses a nice clay made from natural minerals like mica, kaolin and quartz, plus having a high content of iron oxide. This clay -also known as purple clay or sand–is porous and unglazed. It has the nice quality of absorbing the characteristics of the beverage. The advantage is that the clay assists in even cooking, while “the minerals help retain natural juices, essential nutrients and vitamins,” according to the manufacturer.