colcothar

noun

col·co·thar

ˈkäl-kə-ˌthär

plural -s

: a reddish brown iron oxide left as a residue when ferrous sulfate is highly heated and used formerly in polishing glass and as a pigment

: a moderate reddish brown that is yellower and deeper than roan, yellower, stronger, and slightly darker than mahogany, and yellower, less strong, and slightly darker than oxblood

called also angel red, Coromandel, English red, Mars red, Prussian red, Tuscany

Word History

Etymology

Medieval Latin, from Middle French or Old Spanish; Middle French colcotar, from Old Spanish cólcotar (now colcótar), from Arabic dialect qulquṭār, probably modification of Greek chalkanthos