Mumyoi

The mineral known as Mumyoi, which contains iron oxide and is mined from the Sado Kinzan mines, is used in pottery clay and fired at high temperatures. Sado Kinzan refers to the historic gold and silver mines on Sado Island, Niigata Prefecture, Japan.

Uematsu Toshumi was commissioned to create pottery in Sado. The seals include “Sado,” “Kinzan,” and “Toshumi.” When all three are together, they are referred to as “Sado Kinzan Uematsu Toshumi.”

On July 27, 2024, the Sado Island Gold Mines were added to the World Heritage list.