Definify.com
Webster 1913 Edition
Colcothar
Col′co-thar
(kŏl′kō̍-thẽr)
, Noun.
[NL.
colcothar vitrioli
, fr. Ar. qolqoṭar
.] (Chem.)
Polishing rouge; a reddish brown oxide of iron, used in polishing glass, and also as a pigment; – called also
crocus Martis
. Webster 1828 Edition
Colcothar
COLCOTHAR
,Noun.
The sulphate of iron is called colcothar or chalcite, when the calcination has been carried so far as to drive off a considerable part of the acid.