Cross-section of wazuku iron, Wazuku Iron Kettles: Boiling Hot Water for Tea

Wazuku is the term for a grade of iron (sometimes called “pig iron”) refined by using traditional Japanese smelting methods to extract magnetite iron from sand that is quarried from the mountainsides.
From the Momoyama period to around the Meiji period, cooking pots, water kettles, spouted kettles, and other forms were all produced either by iron casters or by blacksmiths.