Gosu (呉須)
Pigment made of natural cobalt (~5% cobalt content). Historically, magnesium, iron, and aluminum impurities gave this glaze a greyish-blue tone (Crueger et al. 2006:286; Ross 2012:5). Around 1870, gosu was replaced by a chemically-produced and less expensive cobalt oxide that creates a brighter, more intense blue (Jahn 2004:342). While most of the ceramics in this collection are decorated with chemically-produced cobalt, AACC-99-009 appears to have been hand painted with natural gosu pigment.
Top of Imari Asagao Namasu-Zara (Imari pickle dish with morning glory design)
Item Record