Copperas is (are?) the protosulphates of copper, iron and (blue, green
and white copperas) - usually, in English use, the green copperas
(protosulphate of iron or ferrous sulphate (Fe SO4)). It is also called
green vitriol, and is used in dying, tanning, and ink. It does have a
role in ceramics: in 1832, it was reported "the red colour used by the
Chinese is made from a common green vitriol or copperas".
This, and much other useful information, as always, gleaned from the
Oxford English Dictionary.
In message <[log in to unmask]>, Ken Hamilton
<[log in to unmask]> writes
>A friend of mine studying her family history keeps coming across
>copperus works, and has asked me what copperus is. Embarrasingly, I
>don't know, except that you use it to make black dye for textiles, and
>it has nothing to do with copper. Is there any more information on its
>source/method of production/uses? Has it a role in pottery making at
>all (one pottery round Denholme was famous for its black pottery, and
>is next to a copperus works)?
> Thanks
> Ken
>
>----------------------
>Ken Hamilton
>c/o Department of Archaeological Sciences
>University of Bradford
>Richmond Road
>Bradford BD7 1DP
>West Yorkshire UK
>(01274) 235906
>http://www.student.brad.ac.uk/kchamil1/
>http://www.geocities.com/Nashville/Rodeo/2122/ovmm.html
>
>
--
Pat Reynolds
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"It might look a bit messy now, but just you come back in 500 years time"
(T. Pratchett)
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