colcothar

[ kol-kuh-ther ]

/ ˈkɒl kə θər /

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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.

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Also called jewelers' rouge.

Origin of colcothar

1595–1605; <Medieval Latin <Old Spanish colcotar,Spanish Arabic qulquṭār, perhaps <Greek chálkanthos copper sulfate solution

Words nearby colcothar

colcannon, Colchester, colchicine, colchicum, Colchis, colcothar, cold, cold abscess, cold agglutination, cold agglutinin, cold-blooded

How to use colcothar in a sentence

The wooden disc is also employed for this purpose with putty, colcothar, or washed tripoli.
A Dictionary of Arts, Manufactures and Mines|Andrew Ure
When the cork or wooden disc edged with hat felt is used for polishing, putty or colcothar is applied to it.
A Dictionary of Arts, Manufactures and Mines|Andrew Ure
No additional colcothar after the first is required in this part of the process; but only a drop of water from time to time.
A Dictionary of Arts, Manufactures and Mines|Andrew Ure
Emery with oil is used for grinding down, and tin-putty or colcothar for polishing.
A Dictionary of Arts, Manufactures and Mines|Andrew Ure

Colcothar of Vitriol, and Crocus of Mars, are old names for red oxide of iron.
A Dictionary of Arts, Manufactures and Mines|Andrew Ure

British Dictionary definitions for colcothar

colcothar

/ (ˈkɒlkəˌθɑː) /

noun

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