ivor and olive lewis on thu 8 sep 11
Thank you to John Hesselberth for the following point relating to Copper
oxide and Copper Carbonate that are used to colour our glazes
"...copper is the most difficult of all the colorants we commonly use to
keep in a glaze...."
This is a fact that has, to my knowledge, never been explained by Chemists.
Google searches for Copper Silicate brings up a wealth of information which=
,
when examined, seems to be inadequate to explain our conundrum.
One reference to Cu3OSi speaks of an "Etidronic Acid Complex" without
enlightening readers what that means. This seems to be related to some form
of drug.
Perhaps we must accept John's comment as an Article of Faith without
knowing the cause.
Best regards,
Ivor Lewis,
REDHILL,
South Australia
.
.
May Luk on thu 8 sep 11
Dear Ivor;
Anything on these pages of The Chemical Catechism?
http://www.archive.org/stream/chemicalcatechi01parkgoog#page/n371/mode/2up
I wonder if we can make an enquiry with the lab technician at the lab
where they conduct glaze leaching test? The leached copper, where did
it go and what did it become?
Best Regards
May
Brooklyn NY
On Thu, Sep 8, 2011 at 2:47 AM, ivor and olive lewis
wrote:
> Thank you to John Hesselberth for the following point relating to Copper
> oxide and Copper Carbonate that are used to colour our glazes
> "...copper is the most difficult of all the colorants we commonly use to
> keep in a glaze...."
> This is a fact that has, to my knowledge, never been explained by Chemist=
s.
[...]
> Best regards,
> Ivor Lewis,
> REDHILL,
> South Australia
> .
> .
>
--
http://twitter.com/MayLuk
http://www.ceramicsbrooklyn.com/
ivor and olive lewis on fri 9 sep 11
Thanks May for that URL.
I had a look at that page. That was the sort of book my Mother would buy fo=
r
me when I was a child . A truly antique text. I tried a search for Copper
Silicate from that page but it brought nothing to the table'
There is a natural amorphous blue/green compound known as Chrysocolla which
contains Water, Silica and Copper Oxide. My guess is that the colour of thi=
s
substance is derived from the coordination of water molecules to the Copper
atom in a similar fashion to the way Copper Sulphate derives its colour fro=
m
the presence of four water molecules. Someone with contacts in a lab might
be able to do as you suggest..
Good to hear from you again.
Sincere regards,
Ivor
----- Original Message -----
From: "May Luk"
To: "ivor and olive lewis"
Cc: <>
Sent: Friday, September 09, 2011 11:16 AM
Subject: Re: : Food safe rim
> Dear Ivor;
>
> Anything on these pages of The Chemical Catechism?
> http://www.archive.org/stream/chemicalcatechi01parkgoog#page/n371/mode/2u=
p
>
> I wonder if we can make an enquiry with the lab technician at the lab
> where they conduct glaze leaching test? The leached copper, where did
> it go and what did it become?
>
> Best Regards
> May
> Brooklyn NY
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