Historically, those glazes reached the highest point during  the Southern Sung and Northern Sung Dynasties in China（960~1234AD）,then gradually declined and eventually disappeared without successors. In recent years, in Japan, those glazing techniques have been studied and found for modern textures and colors. Those colors are purple, cinnabar （red）, blue-green （like blue eyed）, added on the indigo-blue and blue-white, obtained by coppers mixed with a various other ores, recognized as a type of copper glazes. 天藍壷 Sky indigo-blue jar 115mm diameter 215mm high year 2000 鉄窯変香炉 Iron glaze variant（Tetu yu-hen） incense burner 110mm diameter 225mm high year 2002 天藍茶碗 Sky indigo-blue tea bowl 125mm diameter 86mm high year 2000 蕎麦結晶茶入 Soba kessho natume （buck wheat crystalline glaze, tea container） 70mm diameter 77mm high year 1999