Veena Raghavan on sun 20 aug 06
Hi Lee and anyone else on Clayart who may be able to help.
A Japanese potter friend gave me a little Japanese Antique Cobalt to try for
underglaze decoration. She said she was no longer able to find it in Japan. I
wonder if anyone has heard of this and if they can tell me where she can
obtain it in Japan or better still, in the U.S.
Thanks in advance for you help.
Veena
VeenaRaghavan@cs.com
Donna Nicholas on sun 20 aug 06
When I studied with Kako Morino in Kyoto (1960-62), he used an unrefined cobalt called gosu. He said the best came from China, and, indeed, it gave a soft beautiful blue in his overglaze painting. I suspect that the 'antique cobalt' is an unrefined version of the mineral. I believe that most recently the major source of cobalt is Zaire. Good luck in tracking it down.
I have tried to 'contaminate' the refined cobalt we get here with different oxides with modest results ...... nothing as nice as the gosu.
Donna Nicholas
nicholas12@earthlink.net
EarthLink Revolves Around You.
nancy fornoville on mon 21 aug 06
According to the book "Inside Japanese Ceramics, by Richard L. Wilson, p 114"
"In contrast to the relatively pure cobalt oxide used in the West,
the Japanese traditionally paint in natural cobalt (asbolite or
gosu). This contains various oxide impurities in addition to the
cobalt. The composition averages about 40 percent silica, 25 percent
alumina, 25 percent manganese, 5 percent iron and 5 percent cobalt.
The mixture tends to soften the blue color of cobalt and under a
glaze produces the quiet purplish or grayish blues so prices by
porcelain connoisseurs. Although most gosu was imported from China,
small amounts were found in Japan, mostly in Seto"
greetings,
Nancy Fornoville
At 05:34 21-8-2006, you wrote:
>When I studied with Kako Morino in Kyoto (1960-62), he used an
>unrefined cobalt called gosu. He said the best came from China,
>and, indeed, it gave a soft beautiful blue in his overglaze
>painting. I suspect that the 'antique cobalt' is an unrefined
>version of the mineral. I believe that most recently the major
>source of cobalt is Zaire. Good luck in tracking it down.
>
>I have tried to 'contaminate' the refined cobalt we get here with
>different oxides with modest results ...... nothing as nice as the gosu.
>
>
>
>Donna Nicholas
>nicholas12@earthlink.net
>EarthLink Revolves Around You.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
| |
|
