Jian Zhan, is an unmissable item for tea lovers or fine art collectors. The glazing pattern of this Jian Zhan is normally referred to as 'Full bloom'. The Jian Zhan is 100% food-safe, but should NOT be used in a microwave oven due to the high iron content in the clay body.High firing temperature (around 1300 Celcius),strong reduction, high iron content and crystallization pattern all make the failure rate of Jian Zhan is high.Such an even and nice glaze Jian Zhan is very rare.