jewelers’ rouge

noun

1. colcothar.

noun Chemistry.

1. the brownish-red oxide of iron produced by heating ferrous sulfate: used chiefly as a pigment in paints and theatrical rouge, and as a polishing agent.

noun

1. a finely powdered form of ferric oxide produced by heating ferric sulphate and used as a pigment and as jewellers’ rougeAlso called: crocus