[ kol-kuh-ther ]
/ ˈkɒl kə θər /

noun Chemistry.

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.

Origin of colcothar

1595–1605; < Medieval Latin < Old Spanish colcotar, Spanish Arabic qulquṭār, perhaps < Greek chálkanthos copper sulfate solution
Also called jewelers' rouge. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for colcothar

British Dictionary definitions for colcothar


/ (ˈkɒlkəˌθɑː) /


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

Word Origin for colcothar

C17: from French colcotar, from Spanish colcótar, from Arabic dialect qulqutār
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012