Tsugaruite is a sulfosalt mineral with the chemical formula Pb28As15S50Cl. It was first discovered in 1997 in a thin baryte veinlet at the Yunosawa mine in Ikarigaseki, Aomori. In 1998, the International Mineralogical Association approved it as a new mineral species. The mineral was named for its type locality's location in Japan's Tsugaru Peninsula.