Ocher
Ocher (Ochre), minerals of a soft consistency that rub off, e.g. iron ocher, bismuth ocher, nickel ocher, chromium ocher; ocher par excellence is iron ocher, iron hydroxide mixed with clay, red and yellow to brown, also as burnt ochre, used as a paint; artificially prepared from vitreous iron and soda in the presence of air.
Source: Brockhaus’ Kleines Konversations-Lexikon, 5. Auflage 1911